There's a couple of great games up for grabs on the Epic Games Store right now - both Rage 2 and Absolute Drift: Zen Edition are both free to keep, and are well worth grabbing if you have a few moments.
Rage 2, of course, is only a few years old at this point and is a pretty decent first-person shooter that was co-developed by Avalanche Studios and iD Software. It's a sequel to Rage, and although it was met with a mixed response when it released, I found it really quite enjoyable. In any event, few argue that the gameplay is exactly what you'd expect from a title that has iD's fingerprints on it, so it's well worth grabbing if you ask me - free is free anyway, right?
Absolute Drift: Zen Edition is also a pretty fun game that also appeals to my tastes, honestly. It's a pretty decent driving-em-up (where you mostly try to do said driving while going sideways) - with a top-down perspective that actually makes it an awful lot of fun. There are six different cars and three game modes to master, and while it's not on the same level of production as Rage 2, it's a ton of fun and well worth checking out if you're into that sort of thing.
You've got until the 25th of February to grab them, after which Sunless Sea will be up for grabs.