I enjoyed this game quite a lot but maybe with the first level you could reduce the hardness to help players get into the puzzles quicker. Maybe like a bigger hole just for the first level or something
'All engines and frameworks are allowed - you can use Unity, Unreal, SFML, MonoGame, or something you made (as long as its available for others to use as well)' ok you can use it, have fun!
Well I believe you can but I think you should get confirmation from the rule page. I did make my own game in RPG maker MV for my first game jam and that was fine so it should be fine here