The Mound: Omen of Cthulhu is a co-op Lovecraftian horror with a per-player insanity system

ACE Team — the studio behind Rock of Ages and The Eternal Cylinder — is making The Mound: Omen of Cthulhu, a co-op horror game for up to four players based on H.P. Lovecraft's 1940 novella of the same name. IGN got hands-on time with an early demo and came away genuinely unsettled.

The setting has been shifted from the novella's 1928 Oklahoma to the Valvadian Forests of Chile in 1652 — roughly 9,000 km south and 276 years earlier. Players take on the roles of expedition members aboard the galleon Tempestad, tasked with looting treasure and finding a path to the underground city of K'n-yan, home of the Cthulhu-worshipping K'n-yani. Before each run, the group picks a contract from a pool of options, which determines the landing zone, available gear, and objective. The four playable characters — soldier Alonso de la Torre, hidalgo Don Rodrigo de Medina, a woman named Leonor, and priest Fray Gaspar — have distinct personalities and voice lines but play identically, Left 4 Dead-style. Inventory space is tight, so coordinating roles before heading out matters a lot. One run saw the IGN writer load up on a flintlock pistol, a musket, and ammo to play damage dealer — then a storm rolled in and rendered both guns useless. Maps are hand-crafted with no procedural generation.

The standout mechanic is the per-player insanity system. During the demo, one teammate confidently walked into a pit full of spikes and decomposing bodies — to them, it looked like solid ground with a small shrine. Everyone else watched in confusion until the player dropped in and died. In another instance, the world turned dark blood red for one player, disguising one of the island's undead Y'm-bhi inhabitants as a teammate — right up until it attacked. The developers say these examples are just the surface of what the system can do. There's also a death mechanic with teeth: if a downed player isn't revived in time, the forest absorbs them and spits them back out as a corrupted, uncontrollable version of themselves that hunts the survivors.

On the technical side, The Mound runs on a peer-to-peer model with one player acting as host — no dedicated servers, which should spare it from the shutdown fate hitting other multiplayer games right now. A release date hasn't been announced, but the demo left a strong impression, particularly the insanity system, which looks like one of the more creative takes on co-op horror in recent memory.