The Mermaid Mask Review

Before booting up The Mermaid Mask, it helps to know where SFB Games came from. The small British studio, run by brothers Tom and Adam Vian, has been at this for close to twenty years, cutting its teeth on more than thirty Flash games hosted on Newgrounds.

Buried in that pile was the very first Detective Grimoire, a rough, under-an-hour murder mystery at a small carnival, nothing spectacular, but it already had everything the series would become known for: a quiet detective, a cast full of people hiding something for no reason, and a process of gathering evidence to make them talk.

From there, the studio built up its reputation with Detective Grimoire.

A short, cheap mystery about a man supposedly killed by a swamp cryptid nicknamed Boggy, before really arriving with 2019's Tangle Tower, a much longer and sharper story about a murder inside a house shared by two feuding families. In between all of that, the Vians also made Snipperclips and the throwback horror game Crow Country, so plenty of players know this studio without realizing it's the same team.

The Mermaid Mask lands as the fourth full entry in the Detective Grimoire series and the direct sequel to Tangle Tower, following roughly five years of development. It was released on July 16, 2026, for PC and Mac through Steam, along with PlayStation 5, Switch, and Switch 2, and there's a demo up on Steam if you want to try before you buy.

The developers have also gone out of their way to say plainly that no generative AI went into making it, which is worth mentioning even if it isn't the reason most people will pick it up. You start The Mermaid Mask waking up in the Stonetop Inn, a rundown boarding house sitting in a foggy old fishing town called Silkwirm-on-Sea that's seen better days.

Before you've had a proper night's rest, a strange green light pulls you and Sally down to the harbor, where a new client is waiting with a case that's stranger than usual. This time it's a submarine called the Mortuga, and its owner, a local sailor named Magnus Mortuga, has turned up dead in a locked room with his throat cut and a sealed, ancient stone cauldron resting nearby that supposedly hadn't been opened in years.

Nobody can explain how the killer got in or out, and you're stuck below the waves with a small, eccentric crew while you work out which one of them did it.

The story leans harder into the supernatural side of the world than earlier entries did, weaving old sea myths and mermaid folklore into a family history that keeps circling back around to bloodlines and secrets from the earlier games. Anyone who has played Tangle Tower will recognize several allusions to the same family tree, though they are much more subtle.

It is not the mechanics of the mystery that propel The Mermaid Mask forward; it is the supporting characters. You'll meet a nervous, prickly author wrestling with the pressure of following up his own success, a chipper and strange traveling salesman, a slow and imposing scientist type, a soft-spoken illusionist, and a handful of others who all feel fully formed even when barely any of them matter to the actual murder.

There are eight suspects total, including a quiet, aloof illusionist named Symmetry and a slow-moving, imposing figure named Dr. Zephyr, and by the time you're closing in on the real killer, there's a decent chance you're more attached to the cast than you are invested in catching them.

Part of what makes The Mermaid Mask work is that even the suspects who barely matter to the central murder get their own little arcs and running jokes, so pulling every last line of dialogue out of them never feels like a waste of time. The ending runs longer than past entries and wraps up more of its own loose threads, but a good chunk of it plays out as a straight reveal rather than something you piece together yourself.

You can walk into the finale already knowing how and who, only the motive gets handed to you instead of being uncovered, which costs the ending a bit of earned satisfaction.

Structurally, The Mermaid Mask sticks close to how the series has always worked. You get a first-person view of a hand-painted scene, and your cursor is the only tool you need. Clicking on almost anything, useful or not, earns you a line of dialogue from Grimoire or Sally, so there's basically no pixel hunting and no wasted effort in poking around a room.

Nothing important is highlighted outright, but linger in a spot long enough, and key objects start to glimmer faintly, nudging you along without spelling anything out. Everything you gather gets logged into a running clue list you can pull up any time, and rather than flat pictures, every item now shows up as a rotating 3D model you can spin and inspect from every angle, which is new for the series.

The submarine itself opens up gradually through a map screen, with new rooms unlocking as you dig up reasons to visit them. Once you've got enough on someone, you question them about their history, their connection to the victim, and their alibi, played out as toy-like figures acting the scene on a miniature sub, which shows where everyone claims to have been, far better than just describing it.

All of that gets filed into a case file you can revisit whenever you want, letting you line up one person's story against another's. Once you've built up a strong enough case, a suspicion prompt lets you confront a suspect directly, and that's where you pick out specific evidence, fill in blanks, or arrange phrases to spell out exactly what you think happened.

Getting it wrong doesn't punish you, just a nudge toward the right answer; that same easygoing approach shows up in the hints, pacing, and puzzles too.

Running alongside all of this is a full hint system covering where to go next, which clue to show someone, and how to unlock the next suspicion, and it can be switched off entirely if you'd rather work it out on your own, with subtitles and simple point-and-click controls rounding out the accessibility options.

One rough patch worth knowing about ahead of time is that a suspicion prompt can fail to trigger even after you've technically collected every relevant clue, which usually just means the game wants you to physically open and read each entry in the clue menu rather than glance past it, but it can look and feel like a soft lock if you don't realize that's what's happening.

As for length, estimates vary depending on who's playing and how thoroughly, landing anywhere from around ten hours up toward twenty, which puts The Mermaid Mask well past anything else in the series. Scattered through the submarine are the actual puzzles, and they're a real mixed bag in the best way.

One has you fitting glass lenses over a trio of near-identical portraits, shrinking, enlarging, and warping the faces until a riddle points you toward the right setup. Others will have you fiddling with knobs just as if you were working on an old typewriter, moving shapes around to crack the code of your smartphone, manipulating handles to align sides of rotating shapes, or playing with mirrors to contort faces into a certain form.

No single one requires exact pixel alignment, and there is always the thumbs-up/thumbs-down hint available for a little guidance.

Most take only a few minutes once you understand what's being asked, though a couple can genuinely stump you if the logic doesn't click right away. What makes The Mermaid Mask work for the player is the fact that all the puzzles learned earlier in the game will prepare you for the logic required in the future, and you can recognize the pattern rather than having to start from scratch every time.

What is good about this game is that you can leave a puzzle and try some other one at a later time. On the downside, nearly every one of them here is self-contained, with the answer sitting in the same room as the puzzle itself. That's friendlier for players who don't love puzzle games, but it also means there's nothing like Tangle Tower's slow-burn puzzles, where you'd get a piece early and carry the itch to solve it for hours before it finally clicked.

The Mermaid Mask doesn't really build that kind of anticipation, and it's a step back from the tougher, more layered puzzles found in something like Case of the Golden Idol or the Professor Layton games it sometimes gets compared to, so puzzle fans hoping for a real brain-twister might come away a little underwhelmed.

There's no combat here and nothing resembling an experience or leveling system, since your only real progress is measured in clues found and cases cracked, so grinding simply isn't part of how the game plays out. Visually, The Mermaid Mask keeps the series' hand-painted look while pushing further into 3D than any earlier entry.

The main cast stays drawn and animated in the same expressive 2D style the series has always used, keeping that particular charm intact.

The clues and submarine interiors, meanwhile, are built in 3D and hand-painted over by artist Kindra Dantone to mimic the look of the flat backgrounds. Technical director Tom Vian built a custom outline shader that gives those 3D objects the same wobbly, hand-drawn edge as the 2D art, so the two styles blend rather than clash.

Minor body traits play a large part in character development, such as the author's nervousness as he adjusts his glasses or the salesman's exaggerated body language, making the suspects feel like living individuals rather than sprites reciting lines. Lighting gets plenty of attention too, with certain rooms bathed in colored glows, like a furnace room tinted an eerie pink, that add atmosphere without hurting readability.

It is remarkable that the confined space of a submarine does not make you feel cramped but instead feels majestic, and the game works seamlessly on both PC and Mac platforms, except for the occasional lag or crashing of the game, which doesn’t interfere with your gameplay experience. Once the game ends, you get a chance to view an art gallery consisting of character and environmental art from the game.

The voice work is where The Mermaid Mask really earns its reputation. Every single line is fully voiced, right down to the smallest, most throwaway object description, with Grimoire voiced by Edwyn Tiong and Sally voiced by Amber Lee Connors, leading a cast that clearly understands the tone the series is going for.

Backing all of it is a full orchestral score performed by the Budapest Art Orchestra.

It's doing a lot of quiet work behind the scenes, with individual characters and locations getting their own musical themes that shift between something like a slow, ceremonial drone in one room and a quicker, tenser track the moment you're deep in a puzzle.

Sound design outside the score holds up its end, too, with practically every object, clue, and menu getting its own small, distinct sound, which keeps the submarine feeling lived-in rather than like a static backdrop you're just clicking through.

Taken as a whole, The Mermaid Mask reads like a confident, comfortable continuation of what this series has always done well rather than a reinvention of it. Compared to the rough Flash game that started it all, or even the sharper Detective Grimoire, this is clearly SFB Games' most ambitious entry yet, and it shows, in the length, voice work, and sheer amount of writing packed into the submarine.

It spends far more of its runtime on conversation and evidence presentation than on pure exploration or puzzle solving, so it depends on what you came in wanting. If character writing and atmosphere hooked you on Tangle Tower or Detective Grimoire, The Mermaid Mask delivers plenty more of that, with an easy-to-love cast and a mystery that leans further into the supernatural than the series has gone before.

If you were hoping the puzzles would take a real step up in complexity, they mostly don't.

The ending resolves more of its own story than Tangle Tower's rushed finish managed, even if part of that resolution gets handed to you rather than earned through your own deduction. According to the developers, this is likely the last Detective Grimoire story for a while.

With their next project heading in a different direction entirely, so if you've been waiting to see certain hanging threads from Detective Grimoire and Tangle Tower properly resolved, The Mermaid Mask is probably as close as that's going to get for now.

The reception has been equally positive, scoring on the scale between a very good grade that is just short of perfect, to a more conservative silver medal grade, and the general consensus is consistent with your own impression of the mask, namely that The Mermaid Mask has a few weak points, but never disappoints.

For a series that started out as a rough hour-long Flash game about a carnival murder, watching it grow into something this polished, this well-acted, and this confident in its own writing is genuinely satisfying to see, even with a puzzle design that plays it a bit safer than longtime fans might have hoped for.