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Green Man Gaming offers Zombies (free) for 24 hours

zombies-free

The first free game has gone live and is now available, as long as users have both Playfire and GMG accounts, and ensure to link them. Follow the instructions on their blog for all the info.

Zombies. game page: http://www.greenmangaming.com/s/us/en/pc/games/action/zombies/