I feel like there isn't any need for moving rooms and healing to be separate buttons since you're never going to be doing both at the same time. I also think there should be more audiovisual feedback for pressing the button. It's hard to tell when it happens. Also, upgrades don't seem to do much. Damage increases and whatnot don't meaningfully change the game in any way, so it doesn't feel as though I've earned much when I get them. Beyond that, though, the game is competent and functional.