To coincide with the release of Wreckateer, Microsoft has launched "Avatar Famestars," a cross-game promotion that allows you to earn "Fame" and unlock Avatar-related bonuses.
In addition to Wreckateer, other games to support Famestar include Full House Poker and A World of Keflings. Future games planned include Avatar Motocross Madness, Fire Pro Wrestling, and Homerun Stars.
Games in the program will include weekly and one-time challenges that earn you "Fame." Those points are then used to unlock Avatar outfits and items, which can be worn or used in other Xbox Live Arcade titles that use Avatars. Famestar will provide three outfits per game, and the extra challenges act as mini-Achievements.
For more details on the program (and a look at the costumes), visit PlayXBLA.