This could have been a GameBoy game. You nailed that feel. And there are genuinely interesting puzzles and mechanics. But I did not play long, because while Mario is pleasing to jump with and use (because Shigeru Miyamoto invested an enormous amount of time making sure that jumping and moving with Mario was fun), your character's jumps feel... wrong, and difficult, in a way that's hard to describe. It feels like I'm always jumping and hitting my head on the ceiling. So you may need to spend time adjusting how your character moves.