Barotrauma is a Space Station 13-y co-op sub game
Delightful deaths
Grab some pals, crowd into a submarine, and dive into an alien sea to die horribly inside a simulation inspired by Space Station 13. That's emergent sim-o-RPG Barotrauma [official site], which is currently available free in open alpha as developers Undertow Games work towards the full release. Delving into the icy waters of Europa, one of Jupiter's moons, different player classes with different responsibilities must work together and keep the sub ship-shape and alien-free to complete missions. And maybe betray their crew, or worse. Here, have a look in this trailer:
As Undertow explain:
"The players join a crew of up to 16 players and try to carry out missions such as salvaging alien artifacts, killing enormous sea creatures and hauling dangerous cargo from outpost to another. The crew won't just have to deal with external threats like the pressure outside the sub or the inhabitants of the ocean, as the submarine itself is a complex contraption with a load of interconnected items and devices which can cause a wide range of non-scripted, dynamic disasters."
Some crew members may have secret objectives of their own to fulfill. Some may even... clown around. It will support singleplayer with AI crewmates but tssh, come on, play with other people.
Like Space Station 13, the dazzlingly complex sim where Quinns had several adventures as a bartender, it looks like Barotrauma has some complex guts. The submarine (you can design your own) is held together by simulation, with ballast, water pressure, the reactor, wiring, and so on all feeding into what happens. Which means you'll have a lot of work if your sub e.g. crashes into a giant spacecrustacean.
(Pitch: Space Crustacean 13, where players control a space crab from the inside like The Numskulls.)
Undertow Games plan to launch Barotrauma as a paid game later this year but, for now, you can download free alpha versions for Windows and Mac Linux [you big silly -ed.].
Undertow have also launched a Steam Greenlight campaign. Yes, Valve do plan to abolish Greenlight but Undertow say that given the unsettled question of how much Steam Direct will charge, they consider it sensible to go for Greenlight now.
If you fancy something lighter, We Need To Go Deeper hit early access the other week and looks more Lovers in a Dangerous Spacetime than Space Station 13.