I like the idea of going around finding keys. It would be a lot more enjoyable though if there was a way to sprint, but maybe you'd consume oxygen faster. Also I picked up some of the brown pile things, I have no idea what they do but I got 5. Also on the 2nd to last floor it is possible to drop down to the door immediately, but doing so prevents you from getting back up, making the game impossible to win. The art looks really good though, good job!