Claude Fable 5.2
SUBLEVEL 07
A one-sentence FPS prompt, 73 autonomous turns, 41 minutes: wet reflective floors and three waves of hover drones in a 128 KB file.
- 41m build
- 128 KB
- ~$16 API cost
- 375 plays
- MIT
- Source
- 3D FPS
- Three.js
- WebGL
- Reflections
Play next
All games
About SUBLEVEL 07
SUBLEVEL 07 is experiment 04 from fable52-fps-repro, a set of independent, reproducible single-prompt experiments inspired by Saltline. It is not Saltline; it is what Fable 5.2 produced when given a one-line FPS request from scratch.
How it was built
The prompt is a single sentence asking for an "insanely detailed", AAA-looking but tiny FPS level, plus an environment note: one HTML file, libraries only from a CDN, and no external models, images or audio. Running in Claude Code, the model worked for 40.8 minutes over 73 turns with no human input. The author measured the cost at $15.96 at official API prices, with a 90.9% cache hit rate, and re-checked the figure line by line.
How it works
- One 128 KB file: Three.js r170 is loaded from jsDelivr; everything else (level geometry, materials, enemies, UI) is generated in the file
- Wet-floor reflections: a flooded underground substation whose floor reflects the corridor in real time
- Combat: a red-dot carbine with reload mechanics against three waves of hovering drones
- Audio: 18 sound effects, all synthesized with the Web Audio API
- Self-testing: the model also wrote an automated script that beats all three waves with zero console errors
Controls & tips
- WASD move, mouse aim, click fire, ESC releases the mouse
- Reload between waves rather than mid-fight; drones arrive in groups
- Compare it with Saltline: about a tenth of the size and a fraction of the build time, yet still a complete loop
Credits
By wquguru, released under the MIT License. The repository also contains the runner scripts, the system prompt and three smaller experiments (audio, materials and models).
SUBLEVEL 07 guide & tips
Objective
Clear three waves of hovering drones in the flooded substation: 3, then 4, then 6 drones (13 in all). The pips at the top show how many are left in the current wave. Clear the last one and you get CONTAINMENT RESTORED. If your health hits zero, it's OPERATOR DOWN and you start again.
Numbers
- You: 100 health. Each drone: 100 health.
- VK-9 carbine: 30-round magazine, 180 rounds in reserve to start.
- Every wave you clear resupplies +90 reserve rounds (up to 300), with a short breather before the next wave.
Tips
- Reload in the breather between waves, not while drones are in your face. "WAVE CLEARED, AMMUNITION RESUPPLIED" is your cue.
- Aim down the sights (right mouse) for accuracy, but you move slower while aiming.
- Sprint (Shift) only works moving forward, and not while aiming or reloading. Use it to break line of sight, then turn and aim.
- Drones fly in and hover. Keep pillars and corridor corners between you and the next group while you reload.
- The end screen shows your time, accuracy and kills. Try for a cleaner run.
- If the frame rate drops, G cycles through three graphics levels.
Controls
| Input | Action |
|---|---|
| W A S D | Move |
| Mouse | Aim |
| Left mouse | Fire |
| Right mouse | Aim down sights |
| R | Reload |
| Shift | Sprint (forward only) |
| G | Graphics quality |
| M | Mute |
| Esc | Release the mouse |
How to play SUBLEVEL 07 online
SUBLEVEL 07 is a single self-contained HTML file (128 KB) hosted on this site. Press Play Game and it runs in an isolated sandbox. You can also download the .html file and open it offline in any modern browser, or read every line in the Inspect Source tab.
Under the hood it uses Three.js, WebGL, and the model spent about 41m building it (roughly $16 at API prices).
Controls
- WASD to Move
- Mouse to Aim/Shoot
- ESC to Unlock
Tip: click inside the game once to capture the mouse, and press ESC to release it. Fullscreen gives the best frame rate on large monitors.
The prompt behind SUBLEVEL 07
The exact instruction wquguru gave Claude Fable 5.2. Copy it from the View Prompt tab above.
Build me a FPS. Insanely detailed quality pls, something that looks visually like it can keep up with AAA. Make it small in scope (like a tiny level) but otherwise impressive photorealistic graphics （环境说明：做成浏览器里能玩的单文件 HTML，只能从 CDN 引入库，不能加载外部模型、图片、音频文件。输出到 ./demos/04-fps/index.html）
SUBLEVEL 07 FAQ
- How many waves are in SUBLEVEL 07?
Three: 3 drones, then 4, then 6. Clearing all 13 ends the level with CONTAINMENT RESTORED.
- Is SUBLEVEL 07 the same as Saltline?
No. It's a separate experiment: Claude Fable 5.2 given a one-sentence FPS prompt from scratch. It took 41 minutes and about $16, against Saltline's 8 hours and about $550, and the file is 128 KB.
- How do I get more ammo?
Each cleared wave adds 90 reserve rounds (up to 300). Reload during the pause between waves.
- Is SUBLEVEL 07 free to play?
Yes. SUBLEVEL 07 runs in your browser for free, with no download, account or install. It is a single HTML file hosted on this site.
- Can I play SUBLEVEL 07 on a phone or tablet?
Not really. It needs a keyboard and mouse and has no touch controls, so play it on a computer.
- Who made SUBLEVEL 07?
SUBLEVEL 07 was made by wquguru, using Claude Fable 5.2. The model spent about 41m on it, roughly $16 at API prices.
