It took me too long on some of the early levels to fully understand how the hit detection worked (For a while I thought boxes were objects and not background). The speed of extensions/retractions also needs to be tweaked. Died on several attempts because I was placed too close to the first obstacle when restarting the level.
Still giving it 5's across the board. The idea is solid, level designs are great. Would love to give a post-game jam version a try.