The Space Marines of the Adeptus Astartes are humanity's übermensch (or a generic term for sci-fi's widely spread “we're the USMC, but in SPACE!”) soldiers. Steam Marines are basically that but with some steampunk aesthetics added for good measure. You’ll lead them in a top-down 2D fashion, where the goal is to kick steam-alien butt and hopefully survive. Imagine XCOM, but with four guys. You may have never expected a turn-based steampunk strategy game in space but that's exactly what you get with Steam Marines.

The spacecraft carrying your marines comes under attack, and the titular troops are taken out of cryosleep to find out what's wrong. Before the game starts you can change the makeup of your squad. The default configuration is to have one of each of the four available classes, which is a good, versatile start. But before long, things might start to look quite different, as casualties mount, replacements are rarely timely, and almost assuredly not up to snuff.