How far you get on Breakdown?
I got up to the point where you get the abiilty to shoot the projectile from your arms...and there's an area shortly after that where enemies WILL gang up on you and you WILL have to deal with about 3 of them blasting their own energy projectiles at you, with no real way to snipe 'em or otherwise take them out without eating tons of damage.
I actually enjoyed a lot of it at first (liked a lot of the platforming touches, the ability to actually see your own limbs with it, the cool evasive maneuvers like backflip, etc)....but you can't effectively aim your weapon because it's so dependent on lock-on.
BTW, for a lot of folks, like me, who are clueless about if their game is pc quality, or what upgrades they need, I found this site: http://www.yougamers.com/games/. Check the "game-o-meter" for a particular game to see if your PC can run it.
For curiosity's sake, I ran the Orange Box test to see, in case Half Life Ep. 3 doesn't get a 360 release, if my PC could run it, as I expect the system requirements to be about identical. I'd need a new video card although my processor, os, and memory are fine.
I also ran the Crysis one. They may as well have played a little digitized laugh at me after I finished running it, though.
Somehow, my computer ranked slightly above the nice little (2) circle.
So nice.