Codemasters' racing game Grid 2 is free for a limited time through the Humble Store. The game normally costs 24.99 euro but for the next 72 hours you can get it for free.
To get the game, just go to the Grid 2 page on the Humble Store, and click "Get the Game". Once you get the game, it will be yours forever. The offer ends on Sunday, March 17 at 10 a.m. PT. But be careful, because the game cannot be redeemed after March 21.