diff --git a/CHANGELOG.md b/CHANGELOG.md
index 354f0e0..29c034c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,9 +5,11 @@
 This update completely breaks the API lol.
 
 - Added "Worlds" which are like Minecraft's own Dimensions
-    - Added Special Cave world
-        - Added Icy Caves
+    - Added Ice World
+    - Added Slime World
 - Added Darkstone
+- Added Glowslime
+- Added Magma
 
 # [Sep 29th 2024] Unnamed Minor Update
 
diff --git a/mods/pyutest/pyutest/init.lua b/mods/pyutest/pyutest/init.lua
index de9cb44..15a597c 100644
--- a/mods/pyutest/pyutest/init.lua
+++ b/mods/pyutest/pyutest/init.lua
@@ -1 +1,20 @@
 PyuTest = {}
+Translate = minetest.get_translator("pyutest")
+
+PyuTest.BLOCK_FAST = 3
+PyuTest.BLOCK_NORMAL = 2
+PyuTest.BLOCK_SLOW = 1
+
+PyuTest.SURFACE_BOTTOM = 1
+PyuTest.OVERWORLD_TOP = 4096
+PyuTest.OVERWORLD_BOTTOM = -65
+
+-- these values are yoinked from VoxeLibre
+-- (https://git.minetest.land/VoxeLibre/VoxeLibre/src/branch/master/mods/MAPGEN/mcl_biomes/init.lua)
+PyuTest.OCEAN_MIN = -15
+PyuTest.DEEP_OCEAN_MAX = PyuTest.OCEAN_MIN - 1
+PyuTest.DEEP_OCEAN_MIN = -31
+
+PyuTest.get_schem_path = function (name)
+  return minetest.get_modpath("pyutest_mapgen") .. "/schematics/"..name..".mts"
+end
diff --git a/mods/pyutest/pyutest_core/blocks.lua b/mods/pyutest/pyutest_core/blocks.lua
index fb9cf15..da804c3 100644
--- a/mods/pyutest/pyutest_core/blocks.lua
+++ b/mods/pyutest/pyutest_core/blocks.lua
@@ -327,7 +327,8 @@ PyuTest.make_building_blocks("pyutest_core:obsidian", "Obsidian", {"pyutest-obsi
 PyuTest.make_building_blocks("pyutest_core:crystal_lantern", "Crystal Lantern", {"pyutest-crystal-lantern.png"}, nil, {
   cracky = PyuTest.BLOCK_FAST
 }, {
-  light_source = minetest.LIGHT_MAX
+  light_source = minetest.LIGHT_MAX,
+  paramtype = "light"
 })
 
 PyuTest.make_building_blocks("pyutest_core:bone", "Bone", {
@@ -390,6 +391,14 @@ PyuTest.make_building_blocks("pyutest_core:slime", "Slime", {"pyutest-slime.png"
   oddly_breakable_by_hand = PyuTest.BLOCK_FAST
 })
 
+PyuTest.make_building_blocks("pyutest_core:glowslime", "Glowslime", {"pyutest-glowslime.png"}, nil, {
+  bouncy = 85,
+  oddly_breakable_by_hand = PyuTest.BLOCK_FAST
+}, {
+  paramtype = "light",
+  light_source = minetest.LIGHT_MAX
+})
+
 PyuTest.make_node("pyutest_core:sponge", "Sponge", {
   oddly_breakable_by_hand = PyuTest.BLOCK_FAST
 }, {"pyutest-sponge.png"})
@@ -560,3 +569,11 @@ PyuTest.make_node("pyutest_core:ladder", "Ladder", {
   },
   inventory_image = "pyutest-ladder.png"
 })
+
+PyuTest.make_node("pyutest_core:magma", "Magma", {
+  cracky = PyuTest.BLOCK_NORMAL
+}, {"pyutest-magma.png"}, {
+  paramtype = "light",
+  light_source = 11,
+  damage_per_second = 3
+})
diff --git a/mods/pyutest/pyutest_core/electricity.lua b/mods/pyutest/pyutest_core/electricity.lua
index 18a1d19..ed8990a 100644
--- a/mods/pyutest/pyutest_core/electricity.lua
+++ b/mods/pyutest/pyutest_core/electricity.lua
@@ -1,3 +1,4 @@
+local ELECTRICITY_TICK = 0.02 -- Maybe this will prevent stack overflows?
 local function get_neighbours(pos)
   return {
     vector.new(pos.x + 1, pos.y, pos.z),
@@ -25,19 +26,20 @@ PyuTest.make_button = function (id, desc, groups, tiles)
   }), tiles, {
     is_ground_content = false,
     on_rightclick = function (pos, node, clicker)
-      for _, v in pairs(get_neighbours(pos)) do
-        local n = minetest.get_node(v)
-        local def = minetest.registered_nodes[n.name]
-
-        if def.__on_electricity_activated then
-          def.__on_electricity_activated(v, n, clicker, pos)
-        end
-      end
-
       minetest.sound_play("button", {
         pos = pos,
         gain = 1
       })
+
+      for _, v in pairs(get_neighbours(pos)) do
+        local n = minetest.get_node(v)
+        local def = minetest.registered_nodes[n.name]
+        minetest.after(ELECTRICITY_TICK, function ()
+          if def.__on_electricity_activated then
+            def.__on_electricity_activated(v, n, clicker, pos)
+          end
+        end)
+      end
     end
   })
 end
@@ -49,14 +51,14 @@ PyuTest.make_wire = function (id, desc, groups, color, efn)
 
   PyuTest.make_node(id, desc, PyuTest.util.tableconcat(groups, {
     electric = 1
-  }), {"pyutest-wire.png"}, {
-    drawtype = "signlike",
+  }), {"pyutest-wire.png", "pyutest-wire.png", "pyutest-wire.png", "pyutest-wire.png"}, {
+    drawtype = "raillike",
     color = color,
     paramtype = "light",
     sunlight_propagates = true,
-    selection_box = {
-      type = "wallmounted"
-    },
+    -- selection_box = {
+    --   type = "wallmounted"
+    -- },
     walkable = false,
     inventory_image = "pyutest-wire.png",
 
@@ -70,9 +72,11 @@ PyuTest.make_wire = function (id, desc, groups, color, efn)
           goto continue
         end
 
-        if def.__on_electricity_activated then
-          fn(def, v, n, clicker, pos)
-        end
+        minetest.after(ELECTRICITY_TICK, function ()
+          if def.__on_electricity_activated then
+            fn(def, v, n, clicker, pos)
+          end
+        end)
 
         ::continue::
       end
diff --git a/mods/pyutest/pyutest_core/init.lua b/mods/pyutest/pyutest_core/init.lua
index 0433ece..13c9705 100644
--- a/mods/pyutest/pyutest_core/init.lua
+++ b/mods/pyutest/pyutest_core/init.lua
@@ -1,21 +1,3 @@
-Translate = minetest.get_translator("pyutest_core")
-PyuTest.BLOCK_FAST = 3
-PyuTest.BLOCK_NORMAL = 2
-PyuTest.BLOCK_SLOW = 1
-
-PyuTest.SURFACE_BOTTOM = 1
-PyuTest.OVERWORLD_TOP = 4096
-PyuTest.OVERWORLD_BOTTOM = -70
-
--- these values are yoinked from VoxeLibre
--- (https://git.minetest.land/VoxeLibre/VoxeLibre/src/branch/master/mods/MAPGEN/mcl_biomes/init.lua)
-PyuTest.OCEAN_MIN = -15
-PyuTest.DEEP_OCEAN_MAX = PyuTest.OCEAN_MIN - 1
-PyuTest.DEEP_OCEAN_MIN = -31
-
-PyuTest.get_schem_path = function (name)
-  return minetest.get_modpath("pyutest_mapgen") .. "/schematics/"..name..".mts"
-end
 PyuTestCore_Path = minetest.get_modpath("pyutest_core")
 
 dofile(PyuTestCore_Path.."/utils.lua") -- Utilities
diff --git a/mods/pyutest/pyutest_mapgen/mapgen.lua b/mods/pyutest/pyutest_mapgen/mapgen.lua
index 07c5067..7b7b7e7 100644
--- a/mods/pyutest/pyutest_mapgen/mapgen.lua
+++ b/mods/pyutest/pyutest_mapgen/mapgen.lua
@@ -4,9 +4,26 @@ minetest.register_alias("mapgen_river_water_source", "pyutest_core:water_source"
 minetest.register_alias("mapgen_lava_source", "pyutest_core:lava_source")
 minetest.register_alias("mapgen_singlenode", "air")
 
+local mg_flags = minetest.settings:get_flags("mg_flags")
 local mg_name = minetest.get_mapgen_setting("mg_name")
 minetest.set_mapgen_setting(string.format("mg%s_cavern_threshold", mg_name), "0.20", true)
 
+mg_flags.caverns = true
+mg_flags.dungeons = false
+
+-- https://git.minetest.land/VoxeLibre/VoxeLibre/src/branch/master/mods/MAPGEN/mcl_mapgen_core/init.lua#L127
+local mg_flags_str = ""
+for k,v in pairs(mg_flags) do
+  if v == false then
+    k = "no" .. k
+  end
+  mg_flags_str = mg_flags_str .. k .. ","
+end
+if string.len(mg_flags_str) > 0 then
+  mg_flags_str = string.sub(mg_flags_str, 1, string.len(mg_flags_str)-1)
+end
+minetest.set_mapgen_setting("mg_flags", mg_flags_str, true)
+
 -- Biomes
 
 PyuTest.BIOME_TOPS = {
@@ -20,6 +37,7 @@ PyuTest.BIOME_TOPS = {
   swamp = 10
 }
 
+-- Overworld biome types
 PyuTest.BIOME_TYPES = {
   -- Normal biomes (Forests for example)
   NORMAL = 1,
@@ -99,372 +117,372 @@ PyuTest.register_overworld_biome = function(name, type, opts)
   nopts["node_riverbed"] = nopts["node_riverbed"] or "pyutest_core:gravel_block"
 
   minetest.register_biome(PyuTest.util.tableconcat(nopts, {
-	_pyutest_biome_type = type,
+    _pyutest_biome_type = type,
   }))
 
   minetest.register_biome(PyuTest.util.tableconcat({
-	name = name.."_ocean",
-	node_top = nopts["node_riverbed"],
-	depth_top = 2,
-	node_filler = nopts["node_riverbed"],
-	depth_filler = 3,
-	depth_riverbed = 2,
+    name = name.."_ocean",
+    node_top = nopts["node_riverbed"],
+    depth_top = 2,
+    node_filler = nopts["node_riverbed"],
+    depth_filler = 3,
+    depth_riverbed = 2,
 
-	node_water = nopts["node_water"],
-	node_river_water = nopts["node_river_water"],
+    node_water = nopts["node_water"],
+    node_river_water = nopts["node_river_water"],
 
-	heat_point = nopts["heat_point"],
-	humidity_point = nopts["humidity_point"],
+    heat_point = nopts["heat_point"],
+    humidity_point = nopts["humidity_point"],
 
-	y_max = 0,
-	y_min = PyuTest.OCEAN_MIN
+    y_max = 0,
+    y_min = PyuTest.OCEAN_MIN
   }, {
-	_pyutest_biome_type = PyuTest.BIOME_TYPES.OCEAN,
-	_pyutest_ocean_type = type
+    _pyutest_biome_type = PyuTest.BIOME_TYPES.OCEAN,
+    _pyutest_ocean_type = type
   }))
 
   minetest.register_biome(PyuTest.util.tableconcat({
-	name = name.."_deep_ocean",
+    name = name.."_deep_ocean",
 
-	node_top = nopts["node_riverbed"],
-	depth_top = 2,
-	node_filler = nopts["node_riverbed"],
-	depth_filler = 3,
-	depth_riverbed = 2,
+    node_top = nopts["node_riverbed"],
+    depth_top = 2,
+    node_filler = nopts["node_riverbed"],
+    depth_filler = 3,
+    depth_riverbed = 2,
 
-	node_water = nopts["node_water"],
-	node_river_water = nopts["node_river_water"],
+    node_water = nopts["node_water"],
+    node_river_water = nopts["node_river_water"],
 
-	heat_point = nopts["heat_point"],
-	humidity_point = nopts["humidity_point"],
+    heat_point = nopts["heat_point"],
+    humidity_point = nopts["humidity_point"],
 
-	y_max = PyuTest.DEEP_OCEAN_MAX,
-	y_min = PyuTest.DEEP_OCEAN_MIN,
-	vertical_blend = 5
+    y_max = PyuTest.DEEP_OCEAN_MAX,
+    y_min = PyuTest.DEEP_OCEAN_MIN,
+    vertical_blend = 5
   }, {
-	_pyutest_biome_type = PyuTest.BIOME_TYPES.OCEAN,
-	_pyutest_ocean_type = type
+    _pyutest_biome_type = PyuTest.BIOME_TYPES.OCEAN,
+    _pyutest_ocean_type = type
   }))
 
   minetest.register_biome(PyuTest.util.tableconcat({
-	name = name.."_cave",
-	heat_point = nopts["heat_point"],
-	humidity_point = nopts["humidity_point"],
-	y_max = PyuTest.DEEP_OCEAN_MIN - 1,
-	y_min = PyuTest.OVERWORLD_BOTTOM,
+    name = name.."_cave",
+    heat_point = nopts["heat_point"],
+    humidity_point = nopts["humidity_point"],
+    y_max = PyuTest.DEEP_OCEAN_MIN - 1,
+    y_min = PyuTest.OVERWORLD_BOTTOM,
   }, {
-	_pyutest_biome_type = PyuTest.BIOME_TYPES.CAVE,
-	_pyutest_cave_type = type
+    _pyutest_biome_type = PyuTest.BIOME_TYPES.CAVE,
+    _pyutest_cave_type = type
   }))
 end
 
 if PyuTest.is_flat() then
   PyuTest.register_overworld_biome("flat", PyuTest.BIOME_TYPES.NORMAL, {
-      node_top = "pyutest_core:dark_grass_block",
-      node_filler = "pyutest_core:dirt_block",
+    node_top = "pyutest_core:dark_grass_block",
+    node_filler = "pyutest_core:dirt_block",
 
-      y_max = PyuTest.BIOME_TOPS.grassland,
-      y_min = PyuTest.SURFACE_BOTTOM,
+    y_max = PyuTest.BIOME_TOPS.grassland,
+    y_min = PyuTest.SURFACE_BOTTOM,
 
-      heat_point = 50,
-      humidity_point = 50,
+    heat_point = 50,
+    humidity_point = 50,
   })
 
   return
 end
 
 PyuTest.register_overworld_biome("grassland", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.grassland,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.grassland,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 53,
-    humidity_point = 57,
+  heat_point = 53,
+  humidity_point = 57,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("forest", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:dark_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:dark_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 50,
-    humidity_point = 65,
-    _pyutest_biome_flowering = true
+  heat_point = 50,
+  humidity_point = 65,
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("stony_mountains", PyuTest.BIOME_TYPES.WARM, {
-    node_top = "pyutest_core:stone_block",
-    node_filler = "pyutest_core:stone_block",
+  node_top = "pyutest_core:stone_block",
+  node_filler = "pyutest_core:stone_block",
 
-    y_max = PyuTest.BIOME_TOPS.mountains,
-    y_min = PyuTest.BIOME_TOPS.grassland,
+  y_max = PyuTest.BIOME_TOPS.mountains,
+  y_min = PyuTest.BIOME_TOPS.grassland,
 
-    heat_point = 65,
-    humidity_point = 8
+  heat_point = 65,
+  humidity_point = 8
 })
 
 PyuTest.register_overworld_biome("desert", PyuTest.BIOME_TYPES.DESERT, {
-    node_top = "pyutest_core:sand_block",
-    node_filler = "pyutest_core:sandstone_block",
-    node_riverbed = "pyutest_core:sand_block",
+  node_top = "pyutest_core:sand_block",
+  node_filler = "pyutest_core:sandstone_block",
+  node_riverbed = "pyutest_core:sand_block",
 
-    y_max = PyuTest.BIOME_TOPS.desert,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.desert,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 84,
-    humidity_point = 4
+  heat_point = 84,
+  humidity_point = 4
 })
 
 PyuTest.register_overworld_biome("desert_mountains", PyuTest.BIOME_TYPES.DESERT, {
-    node_top = "pyutest_core:sand_block",
-    node_filler = "pyutest_core:sandstone_block",
+  node_top = "pyutest_core:sand_block",
+  node_filler = "pyutest_core:sandstone_block",
 
-    y_max = PyuTest.BIOME_TOPS.mountains,
-    y_min = PyuTest.BIOME_TOPS.desert,
+  y_max = PyuTest.BIOME_TOPS.mountains,
+  y_min = PyuTest.BIOME_TOPS.desert,
 
-    heat_point = 83,
-    humidity_point = 6
+  heat_point = 83,
+  humidity_point = 6
 })
 
 PyuTest.register_overworld_biome("snowy_mountains", PyuTest.BIOME_TYPES.COLD, {
-    node_dust = "pyutest_core:snow_carpet",
-    node_top = "pyutest_core:snow_block",
-    node_filler = "pyutest_core:snow_block",
+  node_dust = "pyutest_core:snow_carpet",
+  node_top = "pyutest_core:snow_block",
+  node_filler = "pyutest_core:snow_block",
 
-    y_max = PyuTest.BIOME_TOPS.mountains,
-    y_min = PyuTest.BIOME_TOPS.frozen_plains,
+  y_max = PyuTest.BIOME_TOPS.mountains,
+  y_min = PyuTest.BIOME_TOPS.frozen_plains,
 
-    heat_point = 6,
-    humidity_point = 72
+  heat_point = 6,
+  humidity_point = 72
 })
 
 PyuTest.register_overworld_biome("frozen_plains", PyuTest.BIOME_TYPES.COLD, {
-    node_dust = "pyutest_core:snow_carpet",
-    node_top = "pyutest_core:snow_block",
-    node_filler = "pyutest_core:snow_block",
+  node_dust = "pyutest_core:snow_carpet",
+  node_top = "pyutest_core:snow_block",
+  node_filler = "pyutest_core:snow_block",
 
-    y_max = PyuTest.BIOME_TOPS.frozen_plains,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.frozen_plains,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    node_water_top = "pyutest_core:ice_block",
-    depth_water_top = 5,
+  node_water_top = "pyutest_core:ice_block",
+  depth_water_top = 5,
 
-    heat_point = 9,
-    humidity_point = 67
+  heat_point = 9,
+  humidity_point = 67
 })
 
 PyuTest.register_overworld_biome("mushroom_fields", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:mycelium_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:mycelium_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.mushroom_fields,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.mushroom_fields,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 53,
-    humidity_point = 94
+  heat_point = 53,
+  humidity_point = 94
 })
 
 PyuTest.register_overworld_biome("ice_spikes", PyuTest.BIOME_TYPES.COLD, {
-    node_top = "pyutest_core:ice_block",
-    node_filler = "pyutest_core:ice_block",
+  node_top = "pyutest_core:ice_block",
+  node_filler = "pyutest_core:ice_block",
 
-    y_max = PyuTest.BIOME_TOPS.ice_spikes,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.ice_spikes,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    node_water_top = "pyutest_core:ice_block",
-    depth_water_top = 5,
+  node_water_top = "pyutest_core:ice_block",
+  depth_water_top = 5,
 
-    heat_point = 9,
-    humidity_point = 70
+  heat_point = 9,
+  humidity_point = 70
 })
 
 PyuTest.register_overworld_biome("meadow", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:dark_grass_block",
-    node_filler = "pyutest_core:dirt_block",
-    depth_filler = 4,
+  node_top = "pyutest_core:dark_grass_block",
+  node_filler = "pyutest_core:dirt_block",
+  depth_filler = 4,
 
-    y_max = PyuTest.BIOME_TOPS.mountains,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.mountains,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 52,
-    humidity_point = 83,
+  heat_point = 52,
+  humidity_point = 83,
 
-    _pyutest_biome_flowering = true,
-    _pyutest_biome_flowering_extra = true
+  _pyutest_biome_flowering = true,
+  _pyutest_biome_flowering_extra = true
 })
 
 PyuTest.register_overworld_biome("old_growth_forest", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:dark_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:dark_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 45,
-    humidity_point = 92,
+  heat_point = 45,
+  humidity_point = 92,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("snowy_forest", PyuTest.BIOME_TYPES.COLD, {
-    node_dust = "pyutest_core:snow_carpet",
-    node_top = "pyutest_core:snow_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_dust = "pyutest_core:snow_carpet",
+  node_top = "pyutest_core:snow_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    node_water_top = "pyutest_core:ice_block",
-    depth_water_top = 5,
+  node_water_top = "pyutest_core:ice_block",
+  depth_water_top = 5,
 
-    heat_point = 8,
-    humidity_point = 69
+  heat_point = 8,
+  humidity_point = 69
 })
 
 PyuTest.register_overworld_biome("savanna", PyuTest.BIOME_TYPES.WARM, {
-    node_top = "pyutest_core:savanna_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:savanna_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.grassland,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.grassland,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 72,
-    humidity_point = 9
+  heat_point = 72,
+  humidity_point = 9
 })
 
 PyuTest.register_overworld_biome("taiga", PyuTest.BIOME_TYPES.CHILLY, {
-    node_top = "pyutest_core:dark_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:dark_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 28,
-    humidity_point = 72,
+  heat_point = 28,
+  humidity_point = 72,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("birch_forest", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 48,
-    humidity_point = 85,
+  heat_point = 48,
+  humidity_point = 85,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("cherry_grove", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 52,
-    humidity_point = 78,
+  heat_point = 52,
+  humidity_point = 78,
 
-    _pyutest_biome_flowering = true,
-    _pyutest_biome_flowering_extra = true
+  _pyutest_biome_flowering = true,
+  _pyutest_biome_flowering_extra = true
 })
 
 PyuTest.register_overworld_biome("swamp", PyuTest.BIOME_TYPES.WETLAND, {
-    node_top = "pyutest_core:swampy_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:swampy_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.swamp,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.swamp,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 52,
-    humidity_point = 88,
+  heat_point = 52,
+  humidity_point = 88,
 })
 
 PyuTest.register_overworld_biome("old_growth_birch_forest", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 47,
-    humidity_point = 73,
+  heat_point = 47,
+  humidity_point = 73,
 
-    _pyutest_biome_flowering = true,
-    _pyutest_biome_flowering_extra = true
+  _pyutest_biome_flowering = true,
+  _pyutest_biome_flowering_extra = true
 })
 
 PyuTest.register_overworld_biome("aspen_forest", PyuTest.BIOME_TYPES.CHILLY, {
-    node_top = "pyutest_core:aspen_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:aspen_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 25,
-    humidity_point = 63,
+  heat_point = 25,
+  humidity_point = 63,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("redwood_forest", PyuTest.BIOME_TYPES.CHILLY, {
-    node_top = "pyutest_core:podzol_block",
-    node_filler = "pyutest_core:podzol_block",
+  node_top = "pyutest_core:podzol_block",
+  node_filler = "pyutest_core:podzol_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 21,
-    humidity_point = 65,
+  heat_point = 21,
+  humidity_point = 65,
 
-    _pyutest_biome_flowering = true
+  _pyutest_biome_flowering = true
 })
 
 PyuTest.register_overworld_biome("jungle", PyuTest.BIOME_TYPES.WARM, {
-    node_top = "pyutest_core:jungle_grass_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:jungle_grass_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 52,
-    humidity_point = 103,
+  heat_point = 52,
+  humidity_point = 103,
 
-    _pyutest_biome_flowering = true,
-    _pyutest_biome_flowering_extra = true
+  _pyutest_biome_flowering = true,
+  _pyutest_biome_flowering_extra = true
 })
 
 PyuTest.register_overworld_biome("large_mushroom_forest", PyuTest.BIOME_TYPES.NORMAL, {
-    node_top = "pyutest_core:mycelium_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_top = "pyutest_core:mycelium_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.mushroom_fields,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.mushroom_fields,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    heat_point = 53,
-    humidity_point = 98
+  heat_point = 53,
+  humidity_point = 98
 })
 
 PyuTest.register_overworld_biome("vyn_forest", PyuTest.BIOME_TYPES.COLD, {
-    node_dust = "pyutest_core:snow_carpet",
-    node_top = "pyutest_core:snow_block",
-    node_filler = "pyutest_core:dirt_block",
+  node_dust = "pyutest_core:snow_carpet",
+  node_top = "pyutest_core:snow_block",
+  node_filler = "pyutest_core:dirt_block",
 
-    y_max = PyuTest.BIOME_TOPS.forest,
-    y_min = PyuTest.SURFACE_BOTTOM,
+  y_max = PyuTest.BIOME_TOPS.forest,
+  y_min = PyuTest.SURFACE_BOTTOM,
 
-    node_water_top = "pyutest_core:ice_block",
-    depth_water_top = 5,
+  node_water_top = "pyutest_core:ice_block",
+  depth_water_top = 5,
 
-    heat_point = 11,
-    humidity_point = 68
+  heat_point = 11,
+  humidity_point = 68
 })
diff --git a/mods/pyutest/pyutest_mapgen/worlds.lua b/mods/pyutest/pyutest_mapgen/worlds.lua
index 06a69eb..8e87004 100644
--- a/mods/pyutest/pyutest_mapgen/worlds.lua
+++ b/mods/pyutest/pyutest_mapgen/worlds.lua
@@ -26,17 +26,18 @@ PyuTest.register_world = function (options)
     y_min = conf.y_min,
     register_biome = function (o)
       local name = conf.name .. "-" .. o.name
+      local cfg = PyuTest.util.tablecopy(o)
+      cfg.node_stone = cfg.node_stone or conf.node_stone -- Defaults to nil
+      cfg.node_water = cfg.node_water or "air"
 
-      minetest.register_biome(PyuTest.util.tableconcat(o, {
+      minetest.register_biome(PyuTest.util.tableconcat(cfg, {
         name = name,
         depth_top = 0,
         depth_filler = 0,
         y_max = conf.y_max,
         y_min = conf.y_min,
-        node_water = "air",
-        node_river_water = "air",
-        node_cave_liquid = "air",
-        vertical_blend = 5
+        node_river_water = cfg.node_water,
+        node_cave_liquid = cfg.node_water,
       }))
 
       return name
@@ -47,30 +48,106 @@ PyuTest.register_world = function (options)
         y_max = conf.y_max,
         y_min = conf.y_min,
       }))
+    end,
+
+    register_decoration = function (o)
+      minetest.register_decoration(PyuTest.util.tableconcat(o, {
+        y_max = conf.y_max,
+        y_min = conf.y_min
+      }))
     end
   }
 end
 
-SpecialCaveWorld = PyuTest.register_world({
-  name = "special_cave_world",
-  y_max = PyuTest.OVERWORLD_BOTTOM,
-  y_min = PyuTest.OVERWORLD_BOTTOM * 2
+IceWorld = PyuTest.register_world({
+  name = "ice_world",
+  y_max = -400,
+  y_min = -800
 })
 
-local icy_cave = SpecialCaveWorld.register_biome({
+local icy_cavern = IceWorld.register_biome({
   name = "icy_cave",
   node_stone = "pyutest_core:ice_block",
   heat_point = 14,
   humidity_point = 0
 })
 
-SpecialCaveWorld.register_ore({
+IceWorld.register_ore({
   ore_type = "blob",
   ore = "pyutest_core:snow_block",
   wherein = "pyutest_core:ice_block",
   clust_scarcity = 3 * 3 * 3,
   clust_num_ores = 35,
   clust_size = 5,
-  biomes = {icy_cave},
+  biomes = {icy_cavern},
   noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
 })
+
+IceWorld.register_ore({
+  ore_type = "blob",
+  ore = "pyutest_core:crystal_lantern_block",
+  wherein = "pyutest_core:ice_block",
+  clust_scarcity = 5.5 * 5.5 * 5.5,
+  clust_num_ores = 6,
+  clust_size = 5,
+  biomes = {icy_cavern},
+  noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
+})
+
+SlimeWorld = PyuTest.register_world({
+  name = "slime_world",
+  y_max = -1400,
+  y_min = -1800
+})
+
+local slimey_cavern = SlimeWorld.register_biome({
+  name = "slimey_cavern",
+  node_stone = "pyutest_core:slime_block",
+  heat_point = 45,
+  humidity_point = 0
+})
+
+SlimeWorld.register_ore({
+  ore_type = "blob",
+  ore = "pyutest_core:glowslime_block",
+  wherein = "pyutest_core:slime_block",
+  clust_scarcity = 4 * 4 * 4,
+  clust_num_ores = 6,
+  clust_size = 5,
+  biomes = {slimey_cavern},
+  noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
+})
+
+LavaWorld = PyuTest.register_world({
+  name = "lava_world",
+  y_max = -2000,
+  y_min = -2400
+})
+
+local lava_cavern = LavaWorld.register_biome({
+  name = "lava_cavern",
+  node_stone = "pyutest_core:molten_rock_block",
+  heat_point = 100,
+  humidity_point = 0,
+})
+
+LavaWorld.register_ore({
+  ore_type = "blob",
+  ore = "pyutest_core:magma",
+  wherein = "pyutest_core:molten_rock_block",
+  clust_scarcity = 4.5 * 4.5 * 4.5,
+  clust_num_ores = 6,
+  clust_size = 5,
+  biomes = {lava_cavern},
+  noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
+})
+
+LavaWorld.register_decoration({
+  deco_type = "simple",
+  sidelen = 16,
+  fill_ratio = 0.00063,
+  decoration = {"pyutest_core:lava_source"},
+  place_on = {"pyutest_core:molten_rock_block", "pyutest_core:magma"},
+  biomes = {lava_cavern},
+  flags = "all_ceilings"
+})
diff --git a/textures/pyutest-glowslime.png b/textures/pyutest-glowslime.png
new file mode 100644
index 0000000..8311e7c
Binary files /dev/null and b/textures/pyutest-glowslime.png differ
diff --git a/textures/pyutest-magma.png b/textures/pyutest-magma.png
new file mode 100644
index 0000000..8ccae88
Binary files /dev/null and b/textures/pyutest-magma.png differ