I know that you don't work on the game anymore, but can you please work on it a little bit to add a Fullscreen mode
Been working on a Godot 4 version of this game these past few days, unsure if ill release it since I have many unfinished versions that I keep abandoning but it's coming along nicely for now, if I don't release this version I will maybe add some qol stuff (this includes the fullscreen mode you want) to this current version that is out right now.
Right now if you want really want fullscreen mode and are using the non web version (so windows or linux) you can look up how to force fullscreen mode for a godot 3 game with command line parameters