Only the recently remastered version can be purchased for PC.
Over the weekend, as fans of Assassin’s Creed 3 dug fully into the remaster, the base version of the game was delisted from Steam and Uplay. The original game’s Steam page simply stated, “Notice: At the request of the publisher, Assassin’s Creed 3 is no longer available for sale on Steam.” On Uplay, searching for it will only bring up listings for Assassin’s Creed 3 Remastered.
If you already own Assassin’s Creed 3 for either platform, it will still be in your library. Ubisoft has removed the game for future purchase however, which isn’t a new trend in gaming. Dark Souls: Prepare to Die Edition was removed from Steam after Dark Souls Remastered released, for instance.
As for whether Assassin’s Creed 3 Remastered is worth looking into, it has a couple of new features, like a better minimap, increased stealth opportunities, and free-aim for archery. The standalone version is also available for Xbox One and PS4, with the Switch version out in May. If you own the Season Pass for Assassin’s Creed Odyssey, then you’ll get Assassin’s Creed 3 Remastered and Assassin’s Creed Liberation Remastered for free.