化石ほりほり
Free · play online in your browser, no download
Dig out fossils with Horibo the robot: charge each strike to just the right strength, because trying too hard shatters the bone. The README says Claude Code made it.
Official site tanuu5.github.io, verified Nov 3, 2026. Linked as the play address (“▶ Play in your browser”) from the developer's own GitHub repository README (tanuu5/fossil-horihori); 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 siteBrowserReleasedFree
Runs in a desktop or mobile browser. No download.
Browser (no download) · Mobile · Official link verified Nov 3, 2026.
About 化石ほりほり
化石ほりほり (Fossil Horihori) is a free 3D fossil-digging game for the browser, played alongside Horibo, a robot AI. You hold a button to build up force and release it to strike: too weak and nothing comes away, too strong and the fossil cracks and chips, so you aim for the green “just right” band on Horibo's analysis gauge, which narrows as you get closer to the bone. You scan to see where the fossil lies, break through thick soil with the hammer, use the chisel lightly on rust-coloured crust and hard rock, and brush away the last dirt, but scrubbing clean bone wears it down. Once more than 60% of the fossil is exposed you can extract it, or keep digging for a better grade; run out of battery first and the dig fails. There are five dig sites with different times of day and strata, from an ammonite to a whole raptor skeleton; extracted fossils lift out and leave their mould behind. Three difficulty levels change the battery, how fragile fossils are and how strict the brush is. It plays with mouse and keyboard, a gamepad or touch, in Japanese or English. The README credits planning and direction to the developer, たぬ (tanuu5), and development to Claude Code (Claude Opus 5.5, reasoning level XHIGH). Strata, fossils, the robot, sound effects and music are all generated in code, with no image or audio files. Free on the developer's GitHub Pages site; the code is MIT-licensed.
How it was built
VerifiedThe README credits planning and direction to たぬ and development to Claude Code (Claude Opus 5.5, reasoning level XHIGH), and says Claude Code made everything from the game design to the height fields and shaders of the strata and fossils, the robot, the sound effects, the music and the screens. Visuals were checked and fixed by capturing them in headless Chrome on a real GPU, and an automatic digging bot tried the five sites at the three difficulty levels to tune battery amounts and tool strength. The brush restrictions, the difficulty levels and how hints appear were decided from たぬ's impressions after playing. In a note post the developer says that apart from 狐火かぐら, the games in that batch took only a few exchanges, mostly bug reports.
- DeveloperDeveloper's note post of 24 Oct 2026: eight browser works, 化石ほりほり among them, were made with Claude Code (Claude Opus 5.5) and published on GitHub between 9 and 23 Oct 2026. — note (たぬ / tank_ai)
Directed by one developer, with Claude Code (Claude Opus 5.5, XHIGH) doing design, code and testing. Built with three.js; the strata and fossils are height fields rendered with custom shaders, and the sound effects and music are synthesised in code. The game uses no image or audio files and relies on the device's own fonts. Balance was tuned with an automatic digging bot.
- Engine / framework
- Three.js
- Languages
- JavaScript
- Team size
- Not disclosed
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
- Source on GitHub (tanuu5/fossil-horihori, MIT)
- Developer's note post on eight works made in two weeks (Japanese)
Verification notes: AI use, features, controls, languages, licence (MIT) and release date (2026-10-11, v1.0.0, from the README's update history) come from the developer's repository README, read through raw.githubusercontent.com on 5 Nov 2026; the README links the play address, which loaded that day. The remark about a few exchanges and bug reports comes from the note post of 24 Oct 2026, which also says six of the games in that batch support touch controls on smartphones; the README lists touch controls for this one. The bundled script contacts no AI services. 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 as v1.0.0, per the README's update history.
DeveloperGitHub
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
Browser (official site)
No public metrics recorded for this listing.
Not publicly available: Concurrent players (site), Monthly revenue, Gross revenue.
Sales & revenue (all platforms)
Browser game — there are no downloads to count.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| tanuu5/fossil-horihori (README) GitHub · Japanese | Repository | Not confirmed | Nov 3, 2026 |
| Claude Opus 5.5 が2週間で作った8つのブラウザ作品（PVつき） note (たぬ / tank_ai) · Japanese | Devlog | Oct 24, 2026 | Nov 3, 2026 |
Similar games
