Due to the difficulties of getting on live after Christmas, XBOX Live is offering a free downloadable game - Undertow, that would normally be 800 points. Offer is only good through 1/23 - 1/27.
http://www.xbox.com/en-US/games/u/undertowxboxlivearcade/
http://www.xbox.com/en-US/games/u/undertowxboxlivearcade/