This game is fucking awesome. Sadly, Gamestop recently marked it back up from $20 to $40, so you'll have to hunt around to find a cheap copy.
Essentially, it's a mech arena battle game. You more or less roleplay a pilot (a "Wire-Head") and play the entire game as if you were sitting at your PC. Through the cyberspace-like interface, you buy upgrades, converse with other wire heads and bloggers, buy music and arrange playlists, hop to different servers, and remotely control your mech in battle.
The core combat is extremely fast and it'll keep you on your toes. Generally, you can leave the arenas at any time (it really depends on the rules of the match, but normally you can bounce whenever) and cash out your winnings, or you can gamble it by staying in as long as possible, killing every opponent and praying to god you don't get wacked and have to cover your repair bill.
Enemies can cloak themselves in a predator-like fashion, which can make hunting them difficult...but you can do the exact same thing, so it really is an even playing field.
The game is fucking fantastic so far, though the initial learning curve is steep.
The game also supports online play, but since the game bombed and no one bought it, no one plays online. If anyone does wind up picking up the game and wants to rumble online, drop me a line on AIM or something and we'll go at it. :)