The gameplay loop is really fun! Keeps you on your toes throughout the entire game and has some strategy involved too. The art and music complement each other and the game quite nicely. I was able to survive for 153.2 seconds, which I feel is pretty good!
Some random events occuring might spice the gameplay up a bit and add more replayability, but your core gameplay loop is pretty good so it really doesn't need it.
Great job :D