SFB Games reveals locked-room submarine murder mystery The Mermaid Mask

SFB Games has released The Mermaid Mask on PC, PlayStation 5, Nintendo Switch and Nintendo Switch 2, giving Detective Grimoire and Sally a locked-room murder to solve aboard the world’s strangest submarine. The victim, identified in one description as Captain Mortuga, is found dead beside a mysterious cauldron, with blood trailing across the floor and eight suspects left to explain how an impossible crime happened.

The setting does a lot of the heavy lifting. The story unfolds in the pitch-black waters beyond a long-abandoned fishing town, a location that turns the submarine into a sealed stage where every conversation matters and every clue has to earn its place. That is part of why the game stands out in a crowded market: instead of asking players to keep up with live-service systems or action-heavy spectacle, it leans on pacing, writing and deduction, the core ingredients of a point-and-click mystery.

The Mermaid Mask continues SFB Games’ Detective Grimoire series, bringing back the title detective and Sally for another case built around an impossible murder. The studio, based in London, England, is run by brothers Tom Vian and Adam Vian, who began making Flash games together in 2002 under the name The Super Flash Bros. That long run matters here, because the new game reads like a direct extension of the studio’s appetite for story-first adventures that give their puzzles and dialogue room to breathe.

Creative director Adam Vian has also discussed how the game fits into the wider Detective Grimoire future after Tangle Tower, signaling that The Mermaid Mask is meant to carry the series forward rather than simply echo it. The project was announced on Dec. 6, 2023 and was originally slated for 2024, before a release-date trailer on June 6, 2026 said it was out that day.

For players looking for a slower, more focused summer game, that combination is the selling point. One dead captain, one isolated submarine and eight eccentric suspects give The Mermaid Mask a compact mystery structure that favors observation over speed and makes the setting part of the puzzle itself.