I had a pretty fun time playing this game. The core game loop is a simple idea that manages to keep the player 100% engaged, which is great game design I think. There are two things I think could be improved, but I'm sure you already know what they are. Some background music and sfx would do wonders for the game, and there is a massive difficulty spike at a certain point. I really hope you continue working on this game, cause I would love to come back and play it again. Also, look for releasing it on mobile once you do! I feel like I would enjoy this even more with a touch screen.