Where is the challenge?
Great game. Yet the only thing missing (I think you already know) is something called "challenge". The game was so easy there was no point on going on. I got to level 52 and just gave up playing to see he dieing. And my guess from the highscore is that everyone is doing the same. I just choose the second grenade (the one that explodes upon impact) and focus my target in the middle. I was getting about 50% more then I was spending on grenades and blood pressure, so there was just nothing else to do. Every once in a while I did buy the big grenade just to see everyone die (and let me add: give some deep to the level system. As soon as you reach the kills that shop screen pops up and you accidentally buy stuff) but it was pointless. Make the game a little harder, and maybe, just maybe, you got youself some challenge.