-None With this option no one will be able to edit your game at all.
-Levels Users will be able to edit your game with some limitations. They can use the scripts and objects in it in their own games, see and edit the scripting that has been made on the "floor" layer however they won't be able to open any of the scripts nor edit any of the blocks.
This option is commonly used to make kits.
-All Users will be able to see, use, and edit everything in your game.