This rocks my fucking world good sir.
This game has literally kept me entertained for hours, and I'm not done yet! I'm amazed at how much gameplay there is in this game, and i doubt many people have played it as much as me (since 417 people have voted on it so far).... Overall you've done an extremely awesome job at making such an expansive game.
Graphics - The graphics scheme seemed pretty plain and bland to me, but I'm now glad you didn't fuck around with colours everywhere, because A: that would have meant a lot more work for you, and B: Using mostly greys you could concentrate more on detail.
Presentation + Gameplay - considering there are two different 'modes' of the game, I'm very impressed. Also, there were three difficulty levels... i only explored medium difficulty on story mode, because I've been hooked playing the game since i started, haah. So the presentation of all the menus was really nice, and i loved the layout of the weapons display, pricings, cash, etc.
The gameplay... to say the least, is awesome. Definately one of the best games I've played in terms of addictability in a very, very long time.
I found no flaws what-so-ever in the game itself, everything was really smooth, there were heaps of enemies, weapons, levels, etc.
Hah, at the moment I'm up to level 32, but just can't seem to crack it, i'll have to go at it again tomorrow morning :P
Audio - It's really good to see someone not taking heaps of different tracks from multiple authors and rotating them around each level - I like it how you've made a whole theme for your game, and stuck to it.
There were also heaps of good sound effects for all the different events in the game, and that kept it exciting to be constantly stimulized.
All in all, i really, really am enjoying playing this game, and at the moment I'd just like some more cash, so that i can buy a whole lot of weapons to get past these fucking Pods!!! haha.
Oh yeh, and some things i left out: I loved the 'scoring' system - cash for killing enemies, and rewards that kept getting higher for completing levels. Along with the bosses here and there, they proved to be pretty damn difficult :D
I love you for entertaining me so much, please, please make a sequal good sir :D