For a 24-hour period earlier this week, anyone who grabbed Mirage: Arcane Warfare on Steam got it free, and got to keep it. Today, the free promotion torch has been passed on to Monaco: What's Yours Is Mine, a 2013 game about committing heists with friends (and a really good one).
All you have to do is add Monaco to your Steam library before the promotion expires tomorrow, the 8th, at 10 am Pacific, and you can keep it forever. According to the announcement post, grabbing Monaco for free also earns you a 10% pre-order discount on the developer's latest game, Tooth and Tail. Whether or not you want that game, we all may as well give Monaco a try, eh?