If you sign up for and participate in Project Stream — Google’s foray into a streaming video game service, which launched a test back in October — you can get a free copy of Assassin’s Creed Odyssey to keep, on PC.

Ubisoft is dangling the freebie, and some free Helix Credits (the series’ in-game currency) to get folks to participate. Project Stream is currently only compatible with Assassin’s Creed Odyssey, which testers can already fool around with at will just by launching the service. But if they spend at least an hour playing Odyssey in Project Stream before Jan. 15, 2019, they get a free copy on PC, linked to their Uplay account. (Uplay and Google accounts are necessary to participate.)

The 1,000 Helix Credits offered are only for the test period, though. They will not carry over to the full, Uplay-linked game after Jan. 15. But any items purchased with this currency during the trial (we recommend the XP boost, coincidentally 1,000 HC) plus all game saves will carry over to the free game. If you already have Assassin’s Creed Odyssey on PC linked to your Uplay account, sorry, it’s not like you get a second copy or a refund.

We tried out Project Stream with Assassin’s Creed Odyssey back in October and found the gameplay smooth and responsive and the stream quality impressive, especially for a state-of-the-art title needing a lot of performance. Project Stream is a browser-based streaming service (meaning it runs through Google Chrome) On a home Wi-Fi network, it ran just as smoothly using both a gaming PC with ideal specs and a MacBook Pro with less than. Some audio compression was noticeable, but “given the choice between playing the standard PC version of the game and the Project Stream version, I’d probably choose streaming,” our reviewer said.

If you’re interested, Google has more information, including how to sign up for Project Stream.