The puzzles themselves were really satisfying. My main feedback would be that it takes a bit too long to restart the level, and the animation for collecting a key is boring.
Also concerning the keys, what if you made them somehow related to a magnet? Maybe fragments of a big magnet that you could use to reach the last level in the hub? I think it would be cool to lean into the magnet theme with the collectables as well.
The player character feels quite nice to control, and the magnet is very satisfying. Keep up the good work!