https://www.gamespot.com/articles/get-four-free-pc-games-right-now/1100-6461833/

Good news, PC gamers. The online retailer GOG is giving away four games for free right now. It's unclear when they'll go back up to regular price, so if you like free stuff and you have a PC capable of rendering the pixels of retro games, you'll want to pick these up as soon as possible.

The games in question are all from the 1990s. You can grab Tyrian 2000, Shadow Warrior Classic Complete, Stargunner, and Bio Menace without spending a dime. And as with all GOG games, they come DRM-free.