The SteamWorld series is an eclectic—and excellent—mix of titles, as Austin described in his interview with developer Image & Form earlier this month. Twitch Prime subscribers can now own a slice of it for free by picking up SteamWorld Heist, a turn-based strategy game that's a bit like a 2D steampunk XCOM.
It's free until December 27—all you have to do is log into your account and head to the game's Twitch page to claim the deal. And remember, if you're an Amazon Prime subscriber then you get Twitch Prime for free. Head to this page and link your accounts together for in-game loot, ad-free viewing and free games like this one.
I've said it before and I'll say it again: alone, Twitch Prime isn't worth the cost of entry for Amazon Prime, but it's yet another reason to sign up. The games you get are good ones more often than not. Superhot was free last weekend, and The Flame in the Flood, Day of the Tentacle Remastered, Oxenfree and Titan Souls have all been thrown in at one point or another.
PC Gamer didn't review Heist when it came out but Austin's interview should give you a good idea. And for what it's worth, the Steam user reviews are glowing.