The Mound: Omen of Cthulhu review: an Unreal Engine 5 fever dream that gets lost in its own ideas

Developer ACE Team doesn’t really do ‘normal’; after all, the Chilean studio made its name with Rock of Ages, a Monkey Ball meets ancient history physics puzzler. The strange, the slightly surreal, follows the team around. The Mound: Omen of Cthulhu might be its most fitting project yet, because what better genre for a studio like this than Lovecraftian horror, a world where logic falls apart, reality is questionable, and a normal walk through the jungle can end with your trusted companion turning into a three-armed monster? Or did they?

On paper, The Mound is your regular extraction game, as you and up to three other players accept a contract, choose your equipment and leave the creaking safety of your ship, the Tempestad, to venture into a cursed jungle to find lost expedition diaries, treasure and clues leading towards the mysterious Mound itself. Get what you need, make it back alive, spend your rewards on better gear, upgrades, buff-yielding trinkets and do it all again. As I say, it sounds like a regular pitch.

Expeditions are around 20 to 30 minutes, which makes it easy to jump into for a session, and there’s a nice tension running through every mission because you’re constantly weighing up whether to push further for more rewards or cut your losses and escape with the loot you’ve found. It’s here that you need to judge whether you’ve met the quest criteria – how much gold have you found? Did you discover a lost diary for clues to the Mound’s location, or find an abandoned crewmate with a story to tell? – and how much you want to gamble on staying longer than needed. Because the jungle ‘comes alive’ the longer you linger, and doesn’t want you to escape. At its best, I ran close to the wind and escaped with little life, a chest of loot, and ghouls, vines, and worm-people on my heels, tripping and clawing at me. At its worst, an expedition becomes a game of patience – in its slow pace, sluggish combat and frustrating weirdness that never truly explains anything.

Welcome to the jungle

The problem is that The Mound is at its strongest when it’s letting you experience the world around you, and at its weakest when it asks you to do more than passively dawdle in its leafy tension. Because that world – the dense, soaking jungle – is genuinely brilliant. The environment is thick, wet and oppressive, the kind of place where every tree looks like it’s hiding something, and maybe it is, and perhaps it's been designed that way to freak you out. Unreal Engine 5 is used exactly as it should here, creating complex foliage, slick, craggy rocks, and muddy paths that lead to treasures or leave you feeling lost.

The environments in The Mound feel hostile before anything even attacks you. When the weather turns, mist rolls in and the light shifts into strange blood-red tones; howls erupt and echo around you. It feels like you’ve wandered into some lost experimental horror film, a 16th-century Evil Dead, rather than yet another squad-based extraction game.

The best moments are when the game teases danger, alludes to a creature in the tree line, or simply lies to you – a teammate looks like a ghoul or a treasure turns into a pit of spikes. The Mound has a way of getting inside your head because the world design is layered in details that unsettle, whether it's flies scurrying across the game camera or shapes moving in the distance; enemies appear as silhouettes in the fog. The game’s sanity system starts messing with your perception of what’s real.

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It’s properly unsettling stuff, partly because of the pacing – slow, quiet and ambient, with the silence peppered with the pit-a-pat of rain – and then it all starts to build: one and then three ‘corrupted’ crew, a giant tree creature that creaks and cracks to life. The creatures are some of the more memorable horror designs I’ve seen recently. Typical ‘zombies’ are joined by giant centipedes, ghostly figures of lost explorers, a strange crow-like apparition that will ‘awaken’ the jungle if startled, things that drift through the undergrowth as they’ve crawled out of a Lee Cronin nightmare.

But then you have to fight them, and this is where the cracks start to appear, as combat in The Mound is clumsy, slow, tempered by lag, the kind that makes eating life-saving rations feel like time has slowed and cycling the inventory a painfully delayed experience. I suspect the combat is deliberately cumbersome, but that doesn’t always make it enjoyable.

The game wants you to feel vulnerable and plays on the era-specific flintlock weapons, axes, and swords, so firearms are slow to raise, aiming is inaccurate, awkward, and unreliable. Muskets need careful handling, and rain can affect them, which is a nice sim-like survival touch. Still, every encounter feels like a desperate struggle rather than a heroic fight for survival against unimaginable horrors.

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Too weird?

If that sounds good to make the horror work, then it does, sometimes. Other times, it just feels like the game is putting obstacles in your way. There’s a difference between making you feel powerless and ensuring encounters are a chore, and The Mound spends a lot of time walking that fine line, and as much time stumbling off it. The old-fashioned weapons and survival mechanics commit to the idea of stranded explorers surviving against horrific giant bugs in pursuit of riches. Still, the same mechanics also create a sense that nothing quite works, leaving you spending more time wrestling with systems than enjoying the chaos around you.

That same feeling extends to exploration, where getting lost, or at least feeling lost, is part of the experience. The jungle should feel confusing, and you should question whether you’re heading in the right direction and mentally marking the path to safety of your row boat. The game doesn’t give an inch either, with little is explained, and when the very ground is occasionally removed from under you or the tree line altered, voices masked into warbles, the idea of an untrustworthy world becomes less fun and more of a curiosity, or worse, just not much fun.

When your cart, pulled slowly along by a bull you sporadically need to return to to store or retrieve loot, disappears somewhere behind you and the world suddenly fills with monsters, the tension can quickly turn to frustration. There’s something unintentionally funny about desperately trying to escape an eldritch nightmare while your heavily loaded cart ambles along at the speed of a very uninterested farm animal. At the same time, its driver mutters, “We shouldn’t be here”.

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Make some noise (or don't)

Thankfully, playing with friends helps, as you’d expect from any team-based extraction game. (There is a solo mode, and the game tracks difficulty with how many are playing, but The Mound is no place for single-player.) For transparency, though, it was hard to find a full squad during my week-long review period. But the game is built around communication, with proximity chat making every expedition feel more personal, and ensuring that if you do get separated, the weirdness of the jungle begins to creep up. There’s a real sense of isolation as you hear distant gunshots, howls and the eerie sound of a teammate’s horn bellowing around you (the horn calls the cart).

There’s a genuine tension here too, as noise can attract enemies and wake the jungle, so a teammate who recklessly snaps through branches or, indeed, constantly bangs a treasure-seeking gong will get a Paddington-hard stare, if such a thing could be communicated over a headset.

There are no character classes forcing players into roles, so success comes from working together, sharing resources, making use of trinkets and trying not to panic when the jungle starts shifting through its horror gears. I was lost several times and never truly felt safe or sure that when I finally saw a teammate, they really were a teammate, which shows, on a psychological level at least, everything ACE Team is doing is working. Whether it’s actually fun is not always the case.

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