This is a nice little puzzle platformer that has the fundamentals down of designing levels that take a little thought to get through. I do agree that the limited view (not being able to see what's below you before you jump at key points in the game) gets annoying, especially when it's done on the very first key you come by, but by the end of the game I was getting used to just assuming that I would be skewered by spikes if I took any blind jumps. My biggest gripe is that at times it felt like I was moving too slow, especially when having to backtrack or loop around through a level, but I realize that considering how fast the purple guy moves it would get ridiculous if you were to speed it up any more. Maybe the Shift key could accelerate time? At any rate, I didn't have any issues with unresponsive keys or anything. The jumping sound didn't annoy me, but the sound of the boxes breaking when you punch them seemed pretty weak to me. But those are minor points in a game that's overall worth a play for any puzzle platformer fan.