Here is everything actually known. The Steam listing carries no Deck compatibility badge as of this writing, the developers haven't mentioned the Deck in launch communications, and Valve's review usually lands around or after release — so a rating may simply arrive late. Until then the only honest tool is the official spec sheet, and it is not encouraging for a handheld: the minimum calls for an i7-8700K-class CPU, a GTX 1660 SUPER-class 6 GB GPU and an NVMe SSD, on Unreal Engine 5 — with demo players on full desktops already reporting dips below 60 FPS.
What that means for the Deck
The Deck's APU sits meaningfully below that GPU floor, and its 16 GB is shared between system and video memory against a 6 GB dedicated-VRAM minimum. If the game boots at all, the realistic ceiling is low settings, aggressive upscaling and a 30 FPS target — playable-adjacent for a slow horror game, but nobody has proven it yet. The one cheap experiment: the demo is free on Steam. If you own a Deck, install the demo and you'll know more than any spec-sheet reading — that's exactly what we'll do at launch, and this page gets rewritten with measurements.
If you try it anyway
Use the demo first; cap at 30 FPS; set the quality preset to Low with upscaling on Performance; and remember the demo's quirk that several settings only apply after a restart. Co-op and crossplaywork the same from a Deck as from any PC — it's a Steam machine, not a separate platform.
Steam Deck questions
Is The Mound: Omen of Cthulhu Steam Deck Verified?
No rating has been published — not Verified, Playable or Unsupported. Valve's review often lands around launch, so check the store page on July 15.
Will The Mound run on Steam Deck?
Unproven. The minimum spec (GTX 1660 SUPER-class 6 GB GPU, NVMe, UE5) sits above the Deck's hardware, and desktop demo players already report frame dips. If it runs, expect Low settings at a 30 FPS cap. The free Steam demo is the honest test.
Is there a Switch version instead?
No — there is no Switch or Switch 2 version announced. The game ships on PC, PS5 and Xbox Series X|S only.