Not exactly a challenge but it's PlayXBLA related:
http://playxbla.com/avatarfamestar/Everyone dreams of stardom and your avatar is no different! There is of course a price for fame and in this case the currency is dedicating yourself to gaming and lots of it. Sounds rough I know… Should you and your avatar be willing to pay that price then the all new Avatar Famestars program is for you! The exclusive avatar items awarded only in Avatar Famestars marks your avatar as a gaming star! Click Read More to check out all the details of this amazing new way to game, screenshots, and a few of the Avatar item rewards!
Avatar FameStar is a new program from Microsoft Studios that delivers new and exciting ways to play online with your friends and compete for social recognition! Every Avatar FameStar game lets players earn Fame by accomplishing weekly and one time challenges, and with Fame comes rewards! Dress your Avatar with exclusive new outfits and items, and show your achievements off to your friends and competitors. Avatar FameStar puts you in the spotlight, bringing Avatar FameStar games together to reward people who play and compete!
Features:
• Earn Fame in a variety of games, including Wreckateer, and updates to Full House Poker and A World of Keflings to support the new program.
• As you earn Fame, unlock new avatar items and outfits, showing off your skills and achievements inside the games.
• Carry over your Fame from one game to the next – wear your FameStar outfit from Full House Poker in A World of Keflings. As new games release that support Avatar FameStar, you’ll have more ways to show off!
• Future titles that will support Avatar FameStar include Avatar Motocross Madness, Fire Pro Wrestling, and Homerun Stars. Keep an eye out for these and even more exciting new games!
Check out the list below for Avatar Famestar game details, screenshot galleries, and a sneak peak at a few of the avatar awards!