It's simple platformer but it's well done, I like the graphics, they are polished. I think that you can add bigger cooldown for projectiles, because player can shoot them like machine gun. I think that, upgrade system could also enhance your game into higher level. For example, for every eliminated enemy, player gets 1 coin and after every level he can buy better fire rate/more damage/increased speed/higher jump/double and later triple projectiles/fire projectiles etc.