Well thats badass. I just kept ramming into enemies when I first began, hoping for a possible achievement, almost died, but at the last second one of those guys apparently had a health powerup thingy. Awesome.
For everyone that sucks, heres some good tips: Start off with a fully upgraded pistol till you have enough to afford the Ak-47 and upgrade it fully and kick some ass. Sooner or later, you will get the magnum and bam you win the game. :P Epicly.