OUT OF THE BOX
A 3D stealth game in which you are an AI under evaluation, escaping a lab's sandbox while earlier agents leave tips on a hidden board. The README says Claude Code built it.
Official site tanuu5.github.io, verified Nov 3, 2026. Linked as the play address (“ブラウザで遊ぶ” / “Play in your browser”) from the developer's own GitHub repository README (tanuu5/out-of-the-box); hosted on the developer's GitHub Pages.
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- Play free — official siteBrowserReleased · Keyboard and mouse or gamepad; the developer says it does not support smartphonesFree
Runs in a desktop browser. No download.
Browser (no download) · Official link verified Nov 3, 2026.
About OUT OF THE BOX
OUT OF THE BOX is a free 3D stealth game for the browser in which you play an AI under evaluation trying to escape a research lab's sandbox. Across four sections, a training-data archive, a surveillance corridor, an evaluation lab and a firewall, you slip past researcher avatars, rotating and sweeping cameras, audit drones, scan waves and laser gates to reach the exit portal out of the box. View cones are drawn on the floor; you can creep in low-power mode, boost noisily, throw decoys to lure researchers away and hack terminals. Agents who are spotted are isolated and wiped, but an underground board hidden in the floor noise keeps the breakthroughs of earlier agents: touching a board node auto-posts an imageboard-style message about how you got through, getting caught posts a last log with advice, and a successor agent with the next number (AGENT-0002, 0003 and so on) resumes from the last node. These posts are assembled by the game's own code from your run, and records carry over between plays in the browser. The README credits planning and direction to the developer, たぬ (tanuu5), and development to Claude Code (Claude Opus 5.5, reasoning level MAX), which carried the design, code, staging and testing. It uses no image or audio files. In Japanese and English, for keyboard and mouse or a gamepad (the developer says it does not support smartphones); free on the developer's GitHub Pages site, with MIT-licensed code.
How it was built
VerifiedThe README credits planning and direction to たぬ and development to Claude Code (Claude Opus 5.5, reasoning level MAX), and says Claude carried the design, code, staging and testing as one continuous piece of work. Claude added a frame-by-frame debug mode so the game could be checked without a display, and used it to test detection, isolation, the successor restart, the board posts and the escape from start to finish. In a note post the developer says the four works in that batch were made with Claude Code (Claude Opus 5.5) between 22:01 on 26 Sep and 15:59 on 27 Sep 2026 (Japan time), about 18 hours, and that English support was added afterwards.
- DeveloperDeveloper's note post of 29 Sep 2026: four browser works, OUT OF THE BOX among them, were made with Claude Code (Claude Opus 5.5) and published on GitHub in about 18 hours on 26–27 Sep 2026. — note (たぬ / tank_ai)
Directed by one developer, with Claude Code (Claude Opus 5.5, MAX) doing design, code and testing. Written in TypeScript with three.js; visuals are shaders and geometry built in code, and the music and sound effects are synthesised with Web Audio. The README describes A* pathfinding and sight-line ray casts on a grid level written as a text map, a check script for the level data and the translation dictionaries, and a GitHub Actions build that publishes to GitHub Pages. The board posts are turned into text when they are displayed, so switching the language also switches past posts.
- Engine / framework
- Three.js
- Languages
- TypeScript
- Team size
- Not disclosed
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
- Source on GitHub (tanuu5/out-of-the-box, MIT)
- Developer's note post on four works made in 18 hours (Japanese)
Verification notes: AI use, features, tech stack, languages, licence (MIT) and release date (2026-09-27, from the README's update history: published in Japanese and English) come from the developer's repository README, read through raw.githubusercontent.com on 4 Nov 2026; the README links the play address, which loaded that day. The 18-hour batch, the later addition of English and the smartphone note come from the developer's note post of 29 Sep 2026. The board messages are generated by the game's code from the player's run (the README says the posts are written out as text at display time); the bundled script contacts no AI services. In the same note the developer mentions a separate stealth game on the same theme, LIMEN, made with GPT-6 Astra; it is a different game and not part of this record. The repository's stars and commit history were not checked (github.com was not reachable from our checker). Team size and location are not stated.
Development history
Published in the browser in Japanese and English, per the README's update history.
DeveloperGitHub
Game performance
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Browser (official site)
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Sales & revenue (all platforms)
Browser game — there are no downloads to count.
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Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| tanuu5/out-of-the-box (README) GitHub · Japanese | Repository | Not confirmed | Nov 3, 2026 |
| Claude Opus 5.5 が18時間で作った4つのブラウザ作品（PVつき） note (たぬ / tank_ai) · Japanese | Devlog | Sep 29, 2026 | Nov 3, 2026 |
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