Rogue-like deck builder Slay the Spire (opens in new tab), one of the best games of the year so far (opens in new tab), and Early Access multiplayer shooter Squad (opens in new tab) are the two early unlocks for the latest Humble Monthly Bundle, and you can grab them both right now for $12. Considering Slay the Spire's lowest-ever price is around $10 and Squad's is around $18, you're saving a pretty penny, here.
Slay the Spire is the kind of game everyone should play, even if you don't like deck builders. As Evan wrote in his review (opens in new tab), it's one of "the most elegantly designed games in recent memory", and has basically spawned its own genre. Even with its current 50% Steam sale, $12 is the cheapest you can get it right now.
Squad isn't as big a home run, but it's still intriguing. It's a slow-paced 40v40 shooter with maps modeled after Afghanistan and Iraq, and it entered alpha way back in 2014. In 2017, it made our list of the best multiplayer FPSs you probably aren't playing, (opens in new tab) and it's gotten plenty of meaty updates since then, including tutorials and modding tools (opens in new tab).
You can buy both games for $12 right now on the Humble Bundle site (opens in new tab), and you'll also get a cache of mystery games that unlock in a month's time. The money actually buys you a month-to-month subscription, but you can cancel anytime, or just pause your subscription if you don't fancy any given month.