Pier Dash (playable Three.js 3D game)
We wrote these prompts and ran each one once, identically, on Gemini 4 Hydrogen, Gemini 3.8 Flash, and Gemma 4 31B through the Gemini API free tier on 14 November 2026 (America/Denver). Hydrogen and 3.8 Flash used thinking_level=MEDIUM; Gemma 4 has no thinking level. We did not edit the models’ code. Playable frames show the raw HTML or SVG (Three.js CDN URLs were rewritten to a local copy so the iframe does not call the public internet). Dollar figures are equivalent paid-tier list prices — labelled “equivalent paid cost; ran on free tier.” A 429 or quota error stops that model for the rest of the batch; leftover tests wait until the free-tier quota resets at midnight Pacific. Free-tier prompts may be used by Google to improve products. This is not a benchmark: one run per prompt, our tasks, our settings.
The prompt (copyable)
Write a complete playable single-file HTML 3D game using Three.js. Title it Pier Dash. The player runs along a wooden pier collecting lanterns and jumping gaps (space, click, or tap to jump). Include 3 lives, gradually increasing speed, a visible score, and start and game-over screens. Use low-poly original art, no external textures. You may load Three.js from exactly this URL and no other network request: https://unpkg.com/three@0.160.0/build/three.min.js No build step. Return only the HTML document, starting with <!DOCTYPE html>.
Side-by-side playable results
Each frame is sandboxed (scripts allowed, no same-origin). External network is blocked by CSP, except our local Three.js copy where needed.
Gemini 4 Hydrogen
ranrewrote Three.js CDN https://unpkg.com/three@0.160.0/build/three.min.js to local https://gemini4hydrogen.com/original-tests/lib/three.min.js
1m 14s · 18,848 tokens · $0.1404 equiv. paid cost; ran on free tier
maxOutputTokens=65536 · thinking_level=MEDIUM
A polished start overlay titled PIER DASH (Endless Twilight Runner) shows jump controls, +25 pts for lanterns, and 3 lives. After Start Run, a 3D wooden pier runs toward an orange sunset, with a low-poly character, score, lives, and a 1.0x speed label. The score counted up during the first seconds of play. The start overlay uses emoji icons.
Gemini 3.8 Flash
errorThe API returned an error, including after one extra attempt. No output this session.
HTTP 503
No output this session. The Gemini 3.8 Flash API returned HTTP 503 (“high demand”) or dropped the connection. We tried once more after the first failure and did not retry in a loop. This was not a quota / 429 error.
Gemma 4 31B
ranrewrote Three.js CDN https://unpkg.com/three@0.160.0/build/three.min.js to local https://gemini4hydrogen.com/original-tests/lib/three.min.js
2m 30s · 4,235 tokens · $0.0000 equiv. paid cost; ran on free tier
maxOutputTokens=32768 · thinking_level=n/a
The start overlay shows PIER DASH, 3 lives, score 0, and a Start Run button. After start, a 3D wooden pier over water appears with gaps, yellow lanterns to collect, and a blue-box player; the score counted up during the first seconds of play.
Metrics
| Model | Status | Wall time | Input | Thinking | Output | Equiv. paid cost | Finish |
|---|---|---|---|---|---|---|---|
| Gemini 4 Hydrogen | ran | 1m 14s | 162 | 3,216 | 15,470 | $0.1404 * | STOP |
| Gemini 3.8 Flash | error | — | — | — | — | — | — |
| Gemma 4 31B | ran | 2m 30s | 132 | 749 | 3,354 | $0.0000 * | STOP |
* Equivalent paid cost; ran on free tier. Hydrogen $1.50 / $7.50 per 1M; 3.8 Flash $0.75 / $3.75 per 1M through 31 Dec 2026; Gemma listed free ($0.00). Output price includes thinking tokens.
What we observed
- Gemini 4 Hydrogen: A polished start overlay titled PIER DASH (Endless Twilight Runner) shows jump controls, +25 pts for lanterns, and 3 lives. After Start Run, a 3D wooden pier runs toward an orange sunset, with a low-poly character, score, lives, and a 1.0x speed label. The score counted up during the first seconds of play. The start overlay uses emoji icons.
- Gemini 3.8 Flash: No output this session. The Gemini 3.8 Flash API returned HTTP 503 (“high demand”) or dropped the connection. We tried once more after the first failure and did not retry in a loop. This was not a quota / 429 error.
- Gemma 4 31B: The start overlay shows PIER DASH, 3 lives, score 0, and a Start Run button. After start, a 3D wooden pier over water appears with gaps, yellow lanterns to collect, and a blue-box player; the score counted up during the first seconds of play.
Observed facts only; we did not score the models and we did not fix their code.