Good news for Linux gamers! System Shock 2: 25th Anniversary Remaster has been rated as Steam Deck Verified / SteamOS Compatible ahead of release.
In their testing Valve noted it does "not default to external Bluetooth/USB controllers" so you may need to manually swap in the Quick Access Menu. Other than that, you should be good to go when it arrives June 26th.
More about it: "It’s the year 2114 and as you awake from cryo sleep on the FTL ship Von Braun, you are unable to remember who or where you are… and something has gone terribly wrong. Hybrid mutants and deadly robots roam the halls while the cries from the remaining crew reverberate through the cold hull of the ship. SHODAN, a rogue AI bent on the destruction of mankind has taken over and it's up to you to stop her."

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Like most Nightdive Studios remasters, it will come with a whole bunch of added extras. Helping to keep the classic running nicely on modern systems, and hopefully pull in a whole new audience for it. Like me, I never could get into the original but perhaps now I will.
Game Highlights:
- Cross-Play Co-Op multiplayer.
- Choose from 3 branches of the Military: O.S.A, Marines or Navy and experiment with different play styles.
- Up to 144FPS performance with ultra-widescreen support.
- Enhanced Characters, Weapon Models and Animations.
- Additional Mod Support.
- Optimized Controller support.
- Quality of Life Improvements.
- 50 Achievements to unlock.