- Primary Playtime: The main story takes approximately 5 to 6 hours to complete.
- Completionist Run: Earning all 21 Steam achievements requires around 8 to 10 hours.
- Speedrun Potential: Experienced players using a guide can finish the game in 3 to 4 hours.
- Key Factor: Playtime is highly dependent on how quickly you solve the visual 3D puzzles.
- No Penalty: Using the built-in hint system does not affect achievements or completion ratings.
The Mermaid Mask hltb: Completion Times & Playtimes
Released on July 16, 2026, by SFB Games, this hand-painted submarine murder mystery has quickly captured the attention of puzzle and adventure game fans. When planning your journey aboard the Mortuga submarine alongside Detective Grimoire and Sally, understanding The Mermaid Mask hltb (How Long To Beat) metrics can help you pace your gameplay. The game offers a dense, narrative-driven experience filled with intricate locked-room puzzles, character interrogations, and 3D clue inspections.
Because the progression is entirely tied to your ability to solve logical and visual puzzles, playtimes can vary significantly from player to player. Below is a breakdown of the estimated completion times based on different playstyles.
| Playstyle | Estimated Time | Focus Areas |
|---|---|---|
| Main Story Only | 5 - 6 Hours | Core investigations, required deductions, and main storyline progression |
| Completionist (100%) | 8 - 10 Hours | All 21 achievements, optional rooms, and finding every hidden clue |
| Guided / Speedrun | 3 - 4 Hours | Skipping optional dialogue and using direct puzzle solutions |
Getting stuck on complex visual mechanisms, such as the typewriter ring code or the switchboard cables, can easily add 1 to 2 hours to your overall playtime if you choose not to use hints.
Chapter Structure & Walkthrough Progression
The narrative structure of the game is divided into distinct, manageable segments that keep the pacing tight. To optimize your playtime and stay within the average The Mermaid Mask hltb window, it helps to understand the main progression route.
The story begins with a brief prologue at the Stonetop Inn before transitioning into the main investigation, Chapter One: The Curse in the Cauldron, which takes place entirely aboard the massive Mortuga submarine.
The Prologue & Boarding
Start at the Stonetop Inn to review the Case File and wake Sally. Head to the Town Square to inspect the unusual green light before boarding the surfaced Mortuga submarine. Complete the initial Mess Hall snake cabinet puzzle to access the crime scene in the Illusion Theatre.
Opening the Investigation
Examine the locked-room crime scene, inspect the ancient stone cauldron, and complete the first case conclusion. This officially starts Chapter One. Your immediate goal is to unlock the Control Room by solving the portrait card puzzle in the Child's Room and retrieving the Glass Eyeball.
Searching the Crew Quarters
Meet acting captain Sinthia Seafoam and retrieve the Captain's Log. Search the bunk rooms to find the gloomy underwater photograph inside the pig safe and recover the handwritten letter addressed to J.D. Wirman.
The Final Reconstruction
Interview the remaining crew members across the Dream Chamber, Cargo Hold, Engine Room, and Airlock Grotto. Complete the crew-location pinboard to unlock personal investigations, expose Mariana's hidden dictaphone recordings, and reconstruct the murder timeline in the Illusion Theatre.
| Game Phase | Key Locations | Critical Progression Triggers |
|---|---|---|
| Prologue | Stonetop Inn, Town Square, Mess Hall | Wake Sally, board the submarine, open the snake cabinet |
| Chapter 1 (Part 1) | Child's Room, Control Room, Bunk Rooms | Retrieve the Glass Eyeball, recover the Captain's Log |
| Chapter 1 (Part 2) | Cargo Hold, Engine Room, Airlock Grotto | Complete the pinboard, repair the compass, interview Tadpole |
| Finale | Illusion Theatre | Solve all personal investigations and reconstruct the timeline |
Always check the in-game map after a major conversation. The submarine expands gradually, and previously visited rooms will regularly receive new interactive elements.
100% Completionist & Achievement Run Guide
For players aiming to unlock all 21 Steam achievements, the playtime will stretch closer to the 10-hour mark. A completionist run requires you to not only finish the main story but also fully explore optional rooms, find every single piece of evidence, and exhaust all character dialogue.
Many of the achievements are tied directly to solving specific room puzzles, while others require meticulous observation of three-dimensional clues.
| Achievement Category | Confirmed Count | Key Achievements | Mastery Tip |
|---|---|---|---|
| Story Progression | 5 | The Beginning, Case Closed | Unlocks automatically as you progress through the main narrative |
| Puzzle Solving | 10 | Cabinet Cracker, True North | Requires solving specific environmental or mechanical locks |
| Exploration & Collection | 6 | No Stone Unturned, Evidence Collector | Requires rotating every 3D object and finding optional rooms |
100% Perfect Investigation Goals:
- Unlock and read all files on Dirk Dansom's phone
- Complete the optional skull classification grid in the Cabinet of Curiosity
- Identify Mariana Moon's disguised dictaphone and listen to all recordings
- Solve the optional colored orb mechanism in the Bilge
- Complete the pirate, flag, and lighthouse display in the Dome Tank
- Exhaust every single interview and evidence-reaction topic with the 8 suspects
Achievements like 'Private Caller' and 'Recorded for Posterity' are highly missable if you proceed to the final confrontation without fully investigating the phone and dictaphone. Keep a backup save before entering the final reconstruction.
Puzzle Complexity & Playtime Multipliers
The primary factor that will influence your personal The Mermaid Mask hltb experience is how you handle the game's diverse puzzles. Unlike traditional point-and-click adventures that rely on pixel-hunting or obscure item combinations, this title focuses heavily on interactive 3D objects, spatial logic, and testimony analysis.
Visual & 3D Puzzles
- Portrait Cards & Lenses
- Diving Helmet Pipes
- Skull Classification
- Requires rotating objects to find hidden seams, labels, and symbols.
Mathematical & Logic Puzzles
- Mess Hall Snake Cabinet
- Pink Pig Safe
- Control Room Switchboard
- Focuses on shape-to-number conversions and mathematical branching.
Deduction & Testimony Puzzles
- Crew Location Pinboard
- Fill-in-the-Blank Deductions
- Final Reconstruction
- Requires linking physical evidence directly to proven statements.
To help you maintain a steady progression and avoid getting stuck, review the quick solutions for the game's most challenging mandatory puzzles:
| Puzzle Name | Location | Quick Solution Summary |
|---|---|---|
| Snake Cabinet | Mess Hall | Set dials to 3 (triangle), 9 (square+pentagon), 7 (triangle+square), and 4 (square) |
| Portrait Cards | Child's Room | Place Patricia center; use resize and fish-eye lenses on outer dolls |
| Switchboard | Control Room | Connect red cable 1-9, blue cable 3-11, and yellow cable 6-12 |
| Four Compasses | Engine Room | Point yellow left, blue down, pink to 2 o'clock, and red to upper-left |
| Diving Helmet | Airlock Grotto | Rotate dials so every connected pipe route starts and ends with the same symbol |
If you find yourself spending too much time on a single mechanism, do not hesitate to use the in-game hint feature. There is absolutely no penalty, and it will keep your playtime moving smoothly.
Beginner Tips to Optimize Your Playtime
If you want to keep your playthrough efficient without sacrificing the rich story, follow these proven strategies to avoid common progression blocks:
- Rotate 3D Clues Completely: Whenever you collect a physical object, rotate it a full 360 degrees. Zoom in on the base, back, and any visible seams. Many clues, like the Glass Eyeball or the repaired compass, contain vital details hidden on their reverse sides.
- Exhaust Suspect Dialogues: When meeting a suspect for the first time, ask every introductory question. Revisit them whenever you find personal items, such as the Inn Deeds for Sinthia or the letter from Ibis for Wirman.
- Use the Notebook Frequently: The notebook is your best tool for tracking active lines of inquiry. If you are unsure where to go next, look for entries that still lack a definitive conclusion.
- Listen to the Dictaphone: Once you unlock Mariana's pipe-shaped dictaphone, listen to every recording. These private conversations expose critical contradictions that are required to unlock advanced personal investigations.
Most apparent dead ends are caused by a single unread clue reaction or an incompletely inspected 3D object. Before backtracking through the entire submarine, re-examine your newest inventory items.
Frequently Asked Questions
Q: What is the average The Mermaid Mask hltb playtime?
For most players focusing primarily on the main story, the game takes about 5 to 6 hours to complete. If you want to achieve 100% completion and earn all 21 Steam achievements, expect the playtime to be around 8 to 10 hours.
Q: Are there any missable achievements in the game?
Yes, several achievements are missable, particularly those related to fully investigating Dirk's phone, listening to all of Mariana's secret dictaphone recordings, and completing optional room puzzles in the Bilge and Dome Tank before starting the final confrontation.
Q: Does using the hint system affect achievements?
No, using the built-in hint system has absolutely no penalty. It will not lock you out of any achievements, including the 'Perfect Investigation' achievement, making it a great tool to use if you want to avoid progression blocks.
Q: What platforms is the game available on?
The game launched simultaneously on PC (Steam), Nintendo Switch, Nintendo Switch 2, and PlayStation 5 on July 16, 2026. All versions feature the same core story, puzzles, and character investigations.