The reverse-metroidvania idea is really neat. It creates a rising difficulty as you have fewer options to deal with the coming challenges and it creates a meta-puzzle where you have to decide which powerups to give up first to cripple you the least in future areas. It also serves replayability as the game is qualitatively different when you play the areas in a different order.
My main criticism is with the platforming mechanics. They felt very clunky, especially with the overzealous wall-cling that was constantly activating when I didn't want it to.