I think you have a great concept here. I like the visual design of the character and the enemies, and the controls work decently enough. However, I don't think this is the kind of game that you can just have one infinitely-long level for. I think that, if you want this to really work, you need to make discrete levels, potentially with different backgrounds, enemies, and maybe even some sort of boss battle.
Like I said, I think there's a lot of good here, but the single infinite level makes the game kind of pointless, in my opinion.
Best of luck!