The Mound review: Hallucinations and distrust in co‑op play

ACE Team launched The Mound: Omen of Cthulhu on July 15, 2026. Published by Nacon, the game is available on PC, PlayStation 5 and Xbox Series X|S, runs on Unreal Engine 5 and is priced at $29.99 for the standard edition and $39.99 for the deluxe edition. A 20% launch discount was applied at release.

The Mound is a four-player co‑op extraction game built around short expeditions from a central Galleon hub. Teams share a pool of equipment, choose a contract and push into a 1652 jungle to escort an ox wagon while collecting relics and resources. Contracts require either a specific item or a value threshold; successful runs award XP and Tokens that unlock artifacts for future trips. Typical matches last 15 to 20 minutes. Solo play is available; reviewers reported two-player runs often feel balanced, while four-player sessions change the dynamic based on team composition.

Sanity is a core gameplay mechanic. As sanity falls, players experience hallucinations, in-game communications degrade and proximity voice chat can become scrambled. Teammates can appear as hostile figures to each other. The game provides a minimal HUD and no status indicators for other players, so direct voice checks are the main way to confirm a teammate’s condition. When a player dies they are moved to a separate chat channel and lose access to the live proximity channel.

Tools and items trade effectiveness for risk. The matchlock arquebus deals strong damage but has a long reload and is ineffective in rain. The Medallion reveals hidden treasure while drawing nearby enemies. The Mask of Nyarlathotep allows players to bypass some threats at the cost of faster sanity loss and a higher chance of appearing hostile to allies. Movement is slow, reloading is deliberate and there is no jump mechanic, making traversal and route selection part of expedition planning.

Enemies include multiple variants of the Y’m‑bhi-ranged, charging, self‑immolating and baiting types-alongside vine creatures, centipedes triggered by vomiting and explosive plant growths. Thick vegetation, fog and rain reduce movement and visibility and can disable gunpowder weapons, encouraging teams to use caves and structures as shelter. Reviewers noted that hallucinations and alternate routes change encounters even on islands visited previously.

Technical performance varied across systems. Testers reported stable performance on mid‑range PC hardware and on PlayStation 5 with few issues. On a high‑end PC at 4K and maximum settings the game struggled to maintain 60+ fps without frame generation and DLSS, and some stuttering occurred. Crashes were reported as rare. Visuals and audio received attention for dense foliage, water effects, ambient music and a heartbeat sound tied to sanity loss. Scattered lore books offer optional background detail for players who pause to read.

Early reviews highlighted the game’s atmosphere and the social tension produced by proximity chat and a minimal UI, and they noted the lack of map puzzles or objectives that require coordinated action by the whole team. Reviewers also identified optimization work and additional cooperative content-such as new islands and enemy types-as areas for post‑launch updates to expand expedition goals. A publisher‑provided review key was used for coverage.