Sonic 2, free on Steam for a limited time

Link.

Does this even need a introduction? I'm fairly sure even my mom knows who Sonic is by now. And #2 is one of the series true classics.

Part of SEGA's sixtieth anniversary, so might be worth keeping an eye on that. Good on them, that's a ridonculous milestone in tech.

Right now the only other freebee is one of those trial weekends for Total War: Warhammer 2. Don't usually mention those since you don't get to keep the game, but hey, that's a really cool strategy title. Highly recommended if your rig can handle that game, since Creative Assembly really nailed that 'Monster Mash meets hammier then a Hammer movie' feel of Warhammer at its best. Recently got an update to that speed up the turns by A LOT, too, so even people that's previously bounced off might want to give the game another go.