This is a free XBLA game and is not the best game on XBLA by any means. That being said, it is much better than some games that cost 800 MSP or more.
The idea for this games is a great idea, it was just not very well executed. Shooting vehicles racing in the Desert is right up my alley but it takes way too little shooting to take out an enemy racer. You have to depend on your driver to pick up Turret Upgrades but enemy drivers can pick up Turret Downgrades which downgrades your turret one level from what you had previously. Graphics aren't great and the models for the Turrets and Vehicles are mediocre at best.
One of the best things about the game are the racetracks though they have their share of problems. A problem with the racetracks are the obstacles on the track (rocks, etc.) is that collision detection is much bigger than the appearance of the item itself. Driving too close to the rocks will result in your vehicle spinning out and maybe even stopping completely if you are at an odd angle.
If more people played online in this game it would be better than having to play single player against the CPU (which is decent at driving but I don't think they control turrets at all.)
Overall, this is pretty good for a Free XBLA game. It could have been better but at least they had the decency to not charge you for a mediocre game!