The Humble Store's Spring Sale is now underway, with discounts of up to 90 percent on more than 4000 games—and 100 percent on one of them. The sci-fi RTS Ashes of the Singularity: Escalation is free for the taking until Sunday.
To claim your free stuff, point yourself here and click the appropriate button. You'll need to sign up for the Humble Newsletter, if you haven't already; with that taken care of you'll be given a Steam key for your efforts. Note that while the game is free to keep forever after you've claimed it, the keys themselves have a relatively short expiry date of May 14, so be sure to activate it right away.
Even setting aside the fact that it's free, Ashes of the Singularity: Escalation is worth your time. It's a standalone expansion to the 2016 RTS Ashes of the Singularity, which we liked quite a bit, even though the maps and story left us flat. Escalation improves on the original considerably, with new units, interface changes, and a better campaign. In 2017, Stardock "merged" Escalation into Ashes of the Singularity, and discontinued the base game.
Ashes of the Singularity: Escalation is free on the Humble Store until 10 am PT/1 pm ET on May 10. The Humble Store Spring Sale is on until May 21.