Add in even MORE to the "insane" feature and tweak the minetest.conf.example

games/minetest/mods/insanity/init.lua

@@ -36,4 +36,14 @@ minetest.register_on_newplayer(function(player)
 		player:get_inventory():add_item('main', 'nuke:tnt 99')
 	end
 end)
-
+minetest.register_on_punchnode(function(p, node)
+	if minetest.setting_getbool("insane") then
+		if node.name == "default:dirt" or "default:dirt_with_grass" or "default:stone" or "default:sand" then
+		minetest.env:remove_node(p)
+		minetest.env:add_entity(p, "nuke:tnt")
+		nodeupdate(p)
+		end
+	else
+	    return true
+	end
+end)

minetest.conf.example

@@ -142,7 +142,7 @@
 # Gives some stuff to players at the beginning
 #give_initial_stuff = false
 #  Gives players a full inventory of TNT
-#insanity = true
+#insane = true
 # New users need to input this password
 #default_password = 
 # Available privileges: build, teleport, settime, privs, shout