http://www.mountaindewgamefuel.com/

IS this Game Fuel just a blatant Halo 3 marketing campaign? Or is it akin to delicious liquid Skittles in a can? Frankly, you could put a picture of a steaming pile of dog dookie on the front of this can and I'd still buy it and enjoy it. If you like really sweet drinks, you might dig this stuff. It's kind of a mix between Mountain Dew and a citrus-y energy drink. I've gone through about 6 cans in the past few days, which might explain why I flew through Prime 3 so fast.

My guess is primarily about the marketing. 

It tastes like a mixture of two other Mountain Dew flavors (the orange in LiveWire and the cherry in CodeRed) its doubtful that Pepsi really felt the need to make up a new flavor, and that yes it's basically a Halo 3 commercial.