Yep. Free. Nothing. Nada. Zip. Zada. Zero. Zilch. Not a penny. I think that's all the incentive you'll need to get this game. Grab it off the PSN to own ThatGameCompany's beautiful and artistic game for the low price of $0.
Do it fast, though, this deal expires at midnight EST. Looks like it also only applies to US and Canada. Sorry to anyone not in North America.