- The Mermaid Mask steam next fest highlights the transition from the successful demo to the full July 16, 2026 launch.
- Core Gameplay revolves around inspecting 3D clues, questioning eight eccentric suspects, and solving environmental puzzles.
- Major Case focuses on the locked-room murder of Captain Magnus Mortuga inside the Illusion Theatre.
- Completionist Goals include unlocking all 21 Steam achievements by exploring every room and exhausting all dialogue options.
- Platform Support includes Steam, Nintendo Switch, Nintendo Switch 2, and PlayStation 5.
From Steam Next Fest to Full Release: Launch Overview
The journey of The Mermaid Mask steam next fest began as a highly anticipated demo that introduced players to the atmospheric world of the Mortuga submarine. Following its successful showing, the full game officially launched on July 16, 2026. Developed by SFB Games, this hand-painted mystery adventure continues the legacy of Detective Grimoire and Sally Spears. The transition from the demo to the full version allows players to carry over their understanding of the core investigation loop while diving into the deeper mysteries of the "Curse in the Cauldron."
The game has maintained a stellar 99% positive review rating on Steam since its launch. Players are tasked with navigating the intricate corridors of a submarine, rotating 3D objects to find hidden secrets, and piecing together contradictory testimonies. Whether you are a veteran of Tangle Tower or a newcomer who discovered the title during the Steam Next Fest, this guide provides the essential roadmap to solving Captain Mortuga's demise.
| Feature | Details |
|---|---|
| Developer | SFB Games |
| Release Date | July 16, 2026 |
| Primary Genre | Hand-Painted Murder Mystery |
| Protagonists | Detective Grimoire and Sally Spears |
| Setting | The Mortuga Submarine |
| Steam Rating | 99% Positive (as of July 2026) |
If you played the demo during the Steam Next Fest, the initial puzzles in the Mess Hall and Illusion Theatre will feel familiar, but pay close attention to the new 3D inspection points added in the final release.
The Mermaid Mask Walkthrough: The Curse in the Cauldron
The investigation is divided into distinct chapters, beginning with a prologue that sets the stage for the primary mystery. Your objective is to move through the submarine, unlock restricted areas like the Control Room, and establish a timeline of events. The "Curse in the Cauldron" chapter is where the meat of the investigation occurs, requiring you to meet all eight primary suspects and collect the evidence necessary for the final confrontation.
The Prologue Investigation
Start at the Stonetop Inn. Inspect the red Case File and the book titled The Hex of the Helmsmen. After waking Sally, head to the Town Square and examine the unusual green light. Board the Mortuga submarine once it surfaces. Inside, move to the Mess Hall to solve the snake cabinet puzzle before entering the Illusion Theatre to examine the initial crime scene.
Unlocking the Control Room
In Chapter One, navigate to the Child's Room. Solve the portrait card mechanism to obtain the Glass Eyeball. Use this item to meet Symmetry Silkmoth and eventually gain access to the Control Room. Here, you will meet Sinthia Seafoam and recover the Captain's Log by solving the switchboard cable puzzle.
Suspect Interviews and Evidence Collection
Systematically visit the Crew Quarters, Dream Chamber, Cargo Hold, and Engine Room. You must interview all eight suspects: Sinthia, Symmetry, Dirk, Wirman, Zephyr, Mariana, Gripp, and Madam Tadpole. Present every new piece of evidence, such as the Gloomy Underwater Photograph or the Inn Deeds, to trigger new dialogue and contradictions.
The Final Reconstruction
Once all personal investigations are complete in the notebook, return to the Illusion Theatre. You must build the final timeline using proven conclusions. Present the matching physical evidence for each deduction prompt to reveal the culprit and the truth behind the Mermaid Mask.
Many players get stuck because they haven't rotated a 3D object completely. Always ensure you have clicked every highlighted "hotspot" on an item before moving to the next room.
Essential Puzzle Solutions: Master the Mortuga Mechanisms
The puzzles in The Mermaid Mask steam next fest and the full game rely heavily on visual logic and mechanical interaction. Unlike traditional point-and-click games that use abstract riddles, these puzzles are integrated into the environment and the objects you collect. Below are the solutions for the most common roadblocks encountered during the first half of the game.
| Room | Puzzle Name | Solution Summary |
|---|---|---|
| Mess Hall | Snake Cabinet | Set dials to 3 (triangle), 9 (square+pentagon), 7 (triangle+square), 4 (square). |
| Child's Room | Portrait Cards | Place Patricia center/medium doll. Use fish-eye lenses on left/right girls. |
| Control Room | Switchboard | Connect Red 1 to 9, Blue 3 to 11, and Yellow 6 to 12. |
| Bunk Room | Pink Pig Safe | Top branches: 3, 4, 1 (Total 8). Second row: 2, 3, 1 (Total 6). |
| Engine Room | Four Compasses | Yellow: Left. Blue: Down. Pink: 2 o'clock. Red: Upper-left. |
| Airlock | Diving Helmet | Rotate dials so every pipe route starts and ends with the same symbol. |
The "Crew Location Pinboard" in the Cargo Hold only becomes solvable after you have met every living crew member. If you are missing a portrait, you need to explore the remaining rooms first.
Submarine Suspects: Character Profiles and Motives
The strength of the narrative lies in its characters. Each suspect has a unique relationship with the late Captain Mortuga and a secret they are trying to hide. While not everyone is a murderer, their secrecy creates the "locked-room" illusion that Grimoire must shatter.
Sinthia Seafoam
The acting captain and nautical engineer. She hides a Gloomy Underwater Photograph and has secret ties to the Stonetop Inn property deeds.
Symmetry Silkmoth
An illusionist who understands stagecraft and deception. Her knowledge of the Illusion Theatre's hidden spaces makes her a key person of interest.
Dirk Dansom
An energetic actor whose locked phone contains private messages about wanting to "become free," suggesting he was under immense personal pressure.
J.D. Wirman
A writer connected to the supernatural book found at the start. He receives secret correspondence from a mysterious individual known only as Ibis.
Dr. Zacharias Zephyr
A "dream doctor" with a collection of Hex Bottles. His equipment can alter perception, raising questions about the "supernatural" sightings.
Mariana Moon
A historian who secretly uses a pipe-shaped Dictaphone to record the crew. Her recordings are vital for finding contradictions in testimony.
When a character's "Personal Investigation" opens in your notebook, focus on completing it immediately. These resolutions often unlock the next major area of the submarine.
Evidence and Clues: The Full Investigation Catalog
Collecting evidence is more than just clicking on items; it involves a deep dive into the history of the Mortuga. The following table catalogs the essential clues required to progress through the main story and unlock the final case reconstruction.
| Clue Name | Category | Location | Primary Use |
|---|---|---|---|
| Case File | Document | Stonetop Inn | Introduces the murder summary and initial goals. |
| Stone Cauldron | Evidence | Illusion Theatre | Proves Mortuga was killed by something inside it. |
| Captain's Log | Document | Control Room | Reveals Mortuga's private plans and command decisions. |
| Inn Deeds | Document | Women's Bunk | Connects Sinthia and Mortuga to a shared property. |
| Letter from Ibis | Correspondence | Men's Bunk | Exposes J.D. Wirman's secret external relationship. |
| Dictaphone | Recording | Cargo Hold | Provides audio proof of crew secrets and motives. |
| Glass Eyeball | Key Item | Child's Room | Unlocks the eye-shaped lock on the Captain's Cabin. |
Don't forget the Upside-Down Illusion Poster in the theatre. Rotating it in your inventory reveals a second meaning that is crucial for understanding the murder method.
Achievement Hunter: Unlocking Every Secret
For players looking to 100% the game after the The Mermaid Mask steam next fest experience, there are 21 achievements to collect. Most are tied to story progression, but several require meticulous exploration and the completion of optional puzzles in rooms like the Cabinet of Curiosity or the Bilge.
Essential Achievement Checklist:
- Cabinet Cracker: Open the snake cabinet in the Mess Hall.
- Know Your Crew: Meet and question all eight primary suspects.
- True North: Repair the compass mechanism in the Engine Room.
- Master Interrogator: Exhaust all major evidence reactions for the crew.
- No Stone Unturned: Fully inspect every 3D object and optional room.
- Case Closed: Complete the final murder reconstruction.
- Perfect Investigation: Finish the game with all optional content resolved.
The "Private Caller" achievement requires you to read every single message and call log on Dirk's phone. If you close the interface too early, you may need to reload a save to trigger it.
Frequently Asked Questions
Q: Is the The Mermaid Mask steam next fest demo still available?
While the full game launched on July 16, 2026, a demo version is often maintained on the Steam store page for new players to try the prologue before purchasing.
Q: How many endings are there in The Mermaid Mask?
The game features one definitive 'Perfect Investigation' ending, but your ability to reach it depends on whether you have collected all evidence and completed every suspect's personal investigation.
Q: What should I do if I'm stuck on a deduction?
Listen to Sally's feedback. If your deduction fails, she and Grimoire will provide a dialogue hint indicating whether the statement is wrong or if the supporting evidence doesn't match.
Q: Are there any differences between the PC and Console versions?
All versions (Steam, Switch, PS5) contain the same story and 21 achievements/trophies, though the PC version offers direct mouse-based interaction for 3D object rotation.