File 01 · First case
The Borrowed Minute
A clock can tell the truth at the wrong time.
Open case Ready to investigate Editor's Pick
Signal Room
original / detective / mystery / deduction / daily / no-download Playable browser game
Question four witnesses and prove a false alibi. Six free, written cases — no signup or live chatbot. Choose a case ↓
Six original mysteries · No paid hints
Choose a detective case
Every case is available. Progress stays on this browser.
Interview witnesses, compare their statements with the records, and prove a contradiction. Start with The Borrowed Minute or choose another file. The daily selection rotates through these six written cases; dialogue is not generated by a live AI.
File 02 · Sound & timing
The Bell That Never Rang
Sometimes the strongest evidence is a missing sound.
Open case Ready to investigateFile 03 · Document trail
The Warm Carbon Copy
The paper is real. Its date is not.
Open case Ready to investigateFile 04 · Travel window
The Last Ferry Home
An arrival time is not a departure time.
Open case Ready to investigateFile 05 · Sequence
The Missing Negative
A photograph cannot predate its subject.
Open case Ready to investigateFile 06 · Digital evidence
The Cold Backup
A backup remembers only what had happened.
Open case Ready to investigateWant a different challenge? Play twenty questions with Oracle 20 or try a Queens logic puzzle.
About this game
Play Signal Room, a free online detective game: interview four witnesses, inspect records and prove which alibi is false. Six original fictional mysteries turn clocks, ferry routes, document dates, photographs, mechanical evidence and backup timestamps into short investigations. Each file has eight written statements, four records and a fixed explanation. Switch between witnesses, ask visible questions or use topic matching to locate a reply, then select the exact statement and the independent record that contradicts it. The game never labels the culprit for you just because you opened a clue. Wrong submissions give you another chance without deleting your interviews, and two optional nudges can help you find an overlooked detail. Every case is available in the archive, while the daily UTC selection rotates through the same six-case collection. Progress is stored on this device, and shared case links preserve the case without revealing its culprit or proof. This is a written, rule-driven mystery game: it does not connect you to a live person or a generative chatbot. All game logic works locally without an API key or model usage charges.
What to expect
- Runs inside AI Game Lib for a fast start.
- Responsive controls for desktop and mobile. Progress stays in this browser.
- Reviewed for its current catalogue tier.
How to play
- Choose one of four witnesses and ask about their alibi or a specific detail.
- Open the records and compare exact times, places and claims. Reading a clue does not automatically identify it as a contradiction.
- Choose a witness, one of their statements you have heard, and the record that directly disproves it.
- Submit the evidence. A correct proof reveals the full explanation; a wrong submission leaves your investigation intact.
- Use an optional nudge, revisit a saved file, or share a solved case without revealing the answer.
- Click inside the game frame before using keyboard controls.
- Use fullscreen when the canvas or controls need more room.
- If the embedded build stalls, reload the page or open the live build from the top bar.
Quick tips
- Read the exact wording. An alibi may depend on a clock, a route direction or a document date.
- Select the statement and the record that cannot both be true. A suspicious detail alone is not a contradiction.
- Open another witness or use a nudge whenever you need a different angle. Wrong submissions do not erase your work.
FAQ
Is Signal Room a free detective game with no download?
Yes. All six original cases run in your browser with no signup, download, API key or paid hints.
Can I interrogate every suspect?
Each file has four witnesses with two written statements each. Switch between them, select visible questions or search for a topic in their replies.
Does the game use a live AI chatbot?
No. Dialogue and evidence are written and fixed. Topic matching selects an existing reply; it does not generate new facts or connect you to another player.
How do I prove an accusation?
Select the witness, the exact statement you heard, and the record you opened that contradicts it. Naming the culprit without the supporting proof does not close the case.
Is there a new story every day?
The daily UTC selection rotates through a collection of six cases. It does not claim to publish a newly written story every day. The archive lets you play every file immediately.
Keep playing
