The two games available at no cost are Crown Champion: Legends of the Arena and Battle Simulator: Counter Stickman. Users only need to add them to their Steam library before the deadline to keep them.
Crown Champion: Legends of the Arena is a hybrid RPG and management game centered on gladiatorial combat. Players recruit and train fighters, manage resources, and progress through a series of arenas while building reputation. The game was originally released in 2016 and normally sells for a low price, but it has maintained a largely positive reception on Steam.
Battle Simulator: Counter Stickman takes a simpler approach. Players command small groups of stickman units in short battle scenarios. The game is relatively brief and has mixed user reviews, but the limited time commitment makes it easy to try without risk. As with many free-to-keep promotions on Steam, trading cards are included, but card drops are disabled.

To keep either game, users must manually claim it on Steam before January 22. There is no requirement to install them immediately. Once added, the titles stay tied to the account and can be downloaded at any time in the future.
Steam frequently runs free-to-play promotions, especially outside major sales periods. Users who track these offers often add games to their libraries even if they do not plan to play them right away, since there is no downside once the claim is made.
Users who want both games should act before the promotion ends, as Steam typically removes the free option without extensions once the deadline passes.