The rather old but rather good Brütal Legend is available now for free via the Humble Store. The game, created by Tim Schafer, features Jack Black as a roadie transported to a world of heavy metal where he must battle evil foes and having chit-chats with Lemmy and Ozzy Osbourne.
I remember playing this back on PS3, the open world sections were great but the strategy sections were a little clumsy. Still, for free you can’t really complain, head over to the Humble Store to nab a copy on PC.
Source: Humble Store