I like the concept, there are some things to improve. First of all background, Enemies and Character are hard to see sometimes. I think you should also add something to encourage the player to not just instantly die to get the best upgrades. Also maybe a Scoresystem and a statbar where you can see your upgrades? I gotta admit i didnt like the sfx very well. The asthetic and style of the game was great though, you can definetly expand on that! Well Done!