Xbox Live reeled during the holidays as a sudden surge of new users overwhelmed its servers. Microsoft wrote an apology letter to Xbox Live customers and promised a free Xbox Live Arcade game in exchange for their patience during the outages. Today Microsoft revealed that the free game will be the underwater shooter Undertow.

Undertow, developed by Chair Entertainment, is an XBLA original that features three races (Humans, Nemoidian, and Atlantian) fighting beneath the waves on a postapocalyptic Earth where the polar ice caps have melted. It has a 15 level campaign/coop mode and two multiplayers modes for up to 16 players. The game will be available for free download from January 23rd to 27th. The normal price for the game is 800 Microsoft Points, or $10.

The deal might be a disappointment to people who either already own Undertow or don't have any interest in this genre but it's admittedly a pretty good game. As with any giveaway, my expectations were pretty low ("Here's a free copy of our newest game, Guinea Pig Wrangler 5000!") so I appreciate the free game. People who were completely pissed off about the outages won't have their mood altered any, though.