Claude Fable 5.2
A top-down xianxia action game: climb a misty mountain gate, fight its guards and duel the general Li Cang.
雾锁山门 (Mist-Locked Gate) is a top-down 3D xianxia action game: one mountain gate, a fight against the patrols, and a two-phase boss duel with story and voice acting. Your master's last errand is to carry a stand-down order up to the Zhenyue Terrace. The gate has been sealed, and the general who holds it, Li Cang (厉苍), Guardian of the Zhenyue Terrace, has received no such order.
It's the demo game for 歸藏 Game Skill, an agent skill for Claude Code and Codex that writes down the workflow behind it. The author says every creative decision was the AI's: they only asked for a Chinese xianxia setting. The build took about 6 hours and 450 million tokens with Fable 5.2 (some of the testing ran on Opus 5.5), over 7 rounds of play-testing.
The same source builds three versions: this online one (touch controls, quality settings, rebindable keys), a single 33 MB HTML file, and an 8 MiB offline build for Xiaohongshu mini-apps.
Made by 歸藏 (op7418). The skill's docs and scripts are AGPL-3.0, but the game's own content (art, models, voices, music, text) is © 2026 歸藏, all rights reserved: play and share the link, but don't re-host or rebrand it.
Climb through the courtyard and the gate to the Zhenyue Terrace and deliver the stand-down order. Patrols block the way; at the top, Li Cang wakes from a statue and fights you in two phases.
| Action | Keyboard / mouse | Touch |
|---|---|---|
| Move | W A S D | Left stick |
| Attack (出剑) | Left mouse | Button |
| Block (hold) (格挡) | Right mouse | Button |
| Dodge (闪避) | Space | Button |
| Sword art (剑诀) | F | Button |
| Ultimate (万剑归宗) | Q | Button |
| Sword flight (hold) (御剑) | Shift | Button |
| Drink potion (饮药) | E | Button |
| Bag (行囊) | B | Button |
Every key can be rebound in Settings, and there's a preset that swaps block and dodge (dodge on right mouse, block on Space).
Press Play Game above and 雾锁山门 loads from the author's own site (op7418.github.io) inside a sandboxed frame. There is nothing to install.
Under the hood it uses Three.js, WebGL.
On a phone, tap Play and the game opens fullscreen with its own touch controls; hold the phone sideways (on iPhone the game is turned for you).
Parry his attacks to fill his posture. At full posture he kneels for about 3.4 seconds and takes 70% more damage, which is the moment for your ultimate (Q). He has 1,100 health and enters a second phase below 55%.
Press block (right mouse by default) just before the hit lands, within about a quarter of a second. A parry refunds 15 stamina; blocking early only blocks.
Rest at an incense burner to refill your four potions, and pick up 伤药 gourds, which add one more.
Yes. The online version has a touch joystick and buttons for every action. It loads the scene first and streams the rest, so Wi-Fi helps.
Yes. 雾锁山门 runs in your browser for free, with no download, account or install. It loads from the author's own site (op7418.github.io).
Yes. It has its own touch controls. It is a landscape game: tap Play, and the game goes fullscreen and turns sideways.
雾锁山门 was made by 歸藏 (op7418), using Claude Fable 5.2.
The author hasn't published the prompt. Many of these games came out of a long back-and-forth with the model rather than a single prompt.
The source is public at https://github.com/op7418/guizang-game-skill.