It won't cost you anything to download the first episode of Doc and Marty's latest adventure.
It may be April Fools Day, but this offer is totally legit. Seriously. Just ask Telltale Games. The studio has announced that Back to the Future: Episode 1 – It’s About Time is now available for free for the Mac and the PC – just follow the link to Telltale’s Back to the Future homepage – and will continue to be discounted until further notice.
Of course, it’s basically just the ol’ reel-them-in-with-a-bit-of-free-stuff-then-make-them-pay marketing ploy, and Telltale is definitely hoping that a few people will pony up for the rest of the episodes after getting a taste of the first one. Even so, a free game is still a free game, so if you’ve been on the fence about Back to the Future, this is a risk-free opportunity to see what the title is all about.
Source: Telltale Blog