Feels like there's a lot of potential here. I really enjoyed the challenge of staying in the air while dealing with enemies. I can totally see how you could expand with new enemy types, different weapons, maybe little items that spawn randomly that you need to collect to really test your ability to move around.
Also, I think maybe there's a bug where the score doesn't reset between runs so it felt like I was just forever increasing a number instead of trying to beat my previous score.