SublustrumAnnouncements checked 2026-10-13.
Join the October 12-25 open playtest
The open playtest for app 4151300 runs from October 12 through October 25, 2026. Brickworks Games and HypeTrain Digital describe it as Chapter One, the opening of the game. It is not the full release, and Steam still listed the game as coming soon on the check date.
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What the posts say is in it
The October 12 Steam announcement says players can look through the Professor's home, follow what he left there, listen to the house, restore the machinery, and look for a way into the Flickering World. The Games Press release the same day says the test is the opening chapter: the opening locations, the start of the brother's trail, and environmental puzzles where sound is part of the clue. Neither post publishes a puzzle solution. Neither says how many chapters the full game will have.
How to request access
- Open the Steam page for app 4151300.
- Use the request-access control on that page. The October 5 announcement and the October 12 Games Press release both send players there.
- The October 5 post also tells players to add the game to a wishlist.
- The dates those posts give are October 12 through October 25, 2026.
Request access on the Steam page
The posts do not say what to do if a request is not accepted, or how long a request takes. A closed test in September is on the news page, including its dates and the two survey figures the developer published.
The pages used for this answer are listed under Sources, playtest.