Hey temrix:
Make sure you have this line in your MINETEST_FOLDER/minetest.conf file:
Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.
Mind you, it will make all of your worlds start generating flat lands.
If this is not what you want, here's how you make a custom game that has flat worlds:
- Copy the game you want to base it off of. For example, I might copy MINETEST_FOLDER/games/minetest_game and name that copy MINETEST_FOLDER/games/minetest_game_flat
- In that game folder (make sure there's a "game.conf" file in there), make a file called "minetest.conf". In that file write "mg_flags = flat".
- In game.conf, change "name = WHATEVER_THE_NAME_WAS" to "name = WHATEVER_YOU_WANT". For example, "Minetest Game Flat".
- Now start Minetest. When you create the world, you will have the option of making it of the type Minetest Game Flat or whatever you named it. Choose this option.
- Now your world will generate flat, while your other worlds are unaffected.
Personally, I just change the option to flat when I need it and then change it back afterward.