October 12, 2026 | HypeTrain Digital and Brickworks Games have launched the open playtest for Sublustrum, a first-person psychological adventure about mystery, memory, and sound. The playtest is available now through October 25, and a new trailer is out today.

Players can join the playtest through the game’s Steam page and play Chapter One, the opening section of Sublustrum. The team is inviting players to share feedback on their experience as development continues.

In Sublustrum, you arrive at the home of your missing brother and find the machine he had been working on - a device built to immerse a person in the depths of the subconscious. Once restored, it becomes a gateway to the Flickering World, a surreal place shaped by memory and governed by rules you’ll have to uncover for yourself.

Inspired by surrealist art, early cinema, and psychoacoustics, Sublustrum tells a story about grief and the difficulty of letting go. Its dreamlike world is filled with elaborate machinery and unsettling spaces that often feel familiar, but never quite right.

The playtest covers the opening chapter of the game and offers a first look at how Sublustrum plays. Players will explore its opening locations, start following the trail left by the protagonist’s brother, and encounter environmental puzzles where paying attention, especially to sound, is key.

Sound has been at the heart of Sublustrum from the very beginning. The original concept started as an interactive companion to an album by Anthesteria, blending dark ambient with neoclassical influences, and music went on to shape both the game’s atmosphere and its visual identity. Players will tune frequencies, follow voices through static, listen for clues, and interact with machines through sound - with some puzzles taking the idea even further, including a location that works as one giant musical instrument.

Key Features:

A mystery that pulls you deeper: Follow the trail left by your missing brother and uncover what happened to him — and what lies beyond his final experiment.
Listen closely: Sound is part of the gameplay. Tune frequencies, follow voices, pick up audio clues, and use what you hear to solve puzzles.
Explore the Flickering World: Travel through surreal spaces shaped by memories, intricate machinery, and dreamlike environments where reality doesn’t always work as expected.
Puzzles built into the world: Observe your surroundings, experiment with strange devices, and piece together solutions that feel like part of the story rather than standalone challenges.
A classic reimagined: The original 2008 Sublustrum returns as a fully explorable 3D adventure, rebuilt from the ground up by members of the original team.