If you didn't have a chance to finish Assassin's Creed Odyssey playing it on Google's Project Stream, Ubisoft has decided not to let a little thing like ownership interfere with your experience. Anyone who plays the game on Google's game streaming service for at least an hour between now and January 15th (the end of the test), will get a free PC copy via Ubisoft's Uplay service, plus 1,000 helix credits for all Project Stream participants.
Your save data and items — both earned and purchased — will transfer over to the Uplay copy, but unspent credits won't.
And if it's only the siren song of free stuff that has drawn your interest, you can still sign up for Project Stream even now and still earn the free copy. (And, as should be obvious, you'll need to actually be selected as eligible for Project Stream to receive an invite for Project Stream.) Both the game and Google's streaming solution offer a pretty good experience, so that hour shouldn't be spent suffering — at least, as long as your internet connection and ping are fast enough to oblige.
For more specific details, check out Ubisoft's formal announcement below.