I thought this game was well put together and polished. Good music, satisfying and addicting game play, and good difficulty. I think the only downside to this game is that it was quite generic, not much distinguishes it from the crowd. But the game was well made and despite its familiarity it was well put together.
Things I would look into:
The starting gun is way better than the uzi in everyway, I would buff the uzi considerably.
More variation in the enemies
More different weapons
But yeah, I really enjoyed this game and I think it deserves a higher score.