Perhaps the biggest issue with the game from a hardcore perspective is a lack of precision. With many weapons, you only have a small amount of control over where you can fire -- at your opponent, just to the left of them, or just to the right. So if your opponent is on the move, even if you know exactly where they're going, you often can't shoot in their direction because each character has a its own fixed firing arc. It doesn't quite feel like you have the exact control that good single-player shoot-em-ups rely upon. This may be necessary to maintain the game balance, but it makes things feel a bit sloppy.
That said, WarTech is more mainstream-friendly than it puts on. Thanks to simple controls and easy-to-understand shoot-or-be-shot mechanics (with occasional special moves), pretty much anyone can jump into the game and understand what they're doing after a few matches. It's amazing that a shoot-em-up -- set up like a friggin' fighting game -- could be considered a mainstream product, but if you're looking for a simple competitive overhead shooter, there's something here for you.
But then comes the unfortunate damning part: the $60 price tag. While WarTech could pass as a mildly charming budget game (or, better yet, as an Xbox Live Arcade game), it simply doesn't have enough content or depth to justify the standard 360 price tag. Online play and Achievements don't warrant a $60 price for something that would probably sell for less than $20 on the PS2.
Ultimately, the game seems to care more about its roster of sexed-up, possibly underage girls than being a truly competitive game -- and for $60, you should really demand better.
