Would have loved a little more music variety or duration. I think the best part of your game is your level design. Your game's gimmick is pretty straightforward, but you made me care about it and realize some interesting implications of being chained together. Like the last level, getting a key is never bad in games, right? But because of your rules, that first key kills you, and it's very predictable if I just stopped to think about it for a second instead of auto-piloting, but it's so ingrained in me that I did not. Keep breaking expectations.

Two small gripes, I kept trying to place one box on another then only move the lower box; however, you have to move them both or the top just slides off. I feel like this movement should be additive, like walking on a moving train. Then, on that first level with blue and yellow keys, it took me forever to thread that needle jumping back up after I had gotten the first key. Maybe I'm just bad.

I don't see a game.

I don't see a game file, maybe I'm not understanding where it is, is there one uploaded? The thumbnail makes it look pretty cool.

Really fun!