Steam Deck Optimized Settings

Once Human is very punishing on the Deck's quad-core CPU. Even just traversing the game's open world can completely choke it, as you can see on the screenshot below. That said the game is playable, if you're ready to put up with occasional traversal stuttering.

60 FPS Optimized Settings

Once Human can run at a relatively steady 60 FPS on the Steam Deck, just be ready for heavy stuttering, most likely caused by assets streaming in the background which overwhelms the CPU.

To reach 60 FPS set the graphics settings to the "Very Low" preset, turn FSR on, and set it to "Performance." You can also set FSR to "Balanced" if you're happy to play with FPS staying mostly in the 50s.

40 FPS Optimized Settings

The 40 FPS experience is rather enjoyable aside from the aforementioned FPS drops. The combination of the "Middle" preset, "Draw Distance" set to "Low" and FSR set to "Balanced" should do the trick.

You can also try playing the game with the "Low" preset and only setting the "VFX" option to "Middle." This will turn on ambient occlusion and make the game look much better. With "VFX" on "Low" and "Very Low" Once Human looks rather flat since ambient occlusion is disabled.

30 FPS Optimized Settings

To achieve a locked 30 FPS, use the "Middle" preset and set "Draw Distance" to "Low."