Great Scott! Telltale Games is offering episode one of Back to the Future: The Game for Windows and OS X completely free. You're imagining this is an April Fool? Hello? Hello? Anybody home? Huh? Think McFly, think! This is no joke, as they add: "this isn't an April's Fool gimmick or prank! And we're not setting an expiration or cut off date for this free game availability." All you need to do is register for a Telltale Games account, or if you are already an account holder, simply login. Here's a summary of the game:

Marty McFly and Doc Brown's adventures continue in the game, with a completely new story created in collaboration with the film trilogy's co-creator and co-writer Bob Gale. In Episode 1 "It's About Time," Marty is just getting re-acquainted with the 1980's when he finds out that Doc Brown is trapped somewhere in the past; and that he must travel back in time to save the Doc's future! The story continues over 5 episodes, with new games releasing monthly. The third episode, "Citizen Brown," released for PC and Mac earlier this week.