Cool game, has potential for something even more fun. Though I will say, I did find a bit confusing, in my first playthrough, I shoot the bullet and I couldn't shoot more, I was so confused, then I understand that you have to pickup the bullet again, which is a cool concept, but it needs to be more clear in that regard.
What else can be improved is the round-wave system. Like, you can go to the next wave or go to the next round??? where the next round you can buy upgrades.... Like, I feel this need to be improved a bit. The upgrades feel cool, mainly the more bounce, which can makes really cool multi kills once the enemies align properly. also the resolution on web seems bugged, I don't know why.
But overall, pretty cool game, with great potential.