Not to be confused with Abyss Crew that we recently covered, We Need To Go Deeper [Steam, Official Site] is a cooperative submarine exploration game currently in Early Access and it just added Linux support.
It's a 2-4 player LAN and online co-op experience design to make you shout at your friends, but there's AI bots as well for those who can't find anyone to play with.
Linux support officially arrived today, with the release of their 0.7.6 patch which adds a Tactical Periscope View, in-game resolution options, a new secret hat to find and a bunch of bug fixes.
Check out the trailer:
The developers claim it's a roguelike, however, random generation doesn't make a game a roguelike. I'm being careful with my own wording here, as people have pointed this out in the past.
Each game is a new trench to explore with 8 unique biomes and an "AI Dungeon Master" who alters difficulty on the fly (which isn't quite finished). You will be repairing leaks, loading torpedoes, routing power around various systems and you can leave the safety of your sub to explore procedurally generated caves too.
Thanks for the tip, scaine!