Awesome. You really pulled it out of the bag in 4 hours. Great concept, brilliantly executed. The striking and simplistic art style is a strength, as is the concept and gameplay. Obviously the sound could be improved, but as a game, this is great. I'd love for scoring to be added. Please consider this request a bug report, and 'polish' a high score feature in there, because I could definitely sink a lot more time into this.
Thanks for sharing, and WELL DONE for pulling this together in only 4 hours. I'm really glad I got to play it :)