This is a great concept, although it left me wondering what does what sometimes.
For example on the first level I though I was pushing the key.
Or on the last level I still have no idea what the red door did.
Also, I don't think there was a single level requiring [W] or [S]. :P
But nonetheless, the game looks great, and this is a nice mechanic! I would love to play it again if you make more levels for it and have time to clarify some stuff in-game! This has potential! :)