DeepSeek V4.1 Flash Generates a Browser Tactical Shooter in OpenCode in a Single Run: A Field Report on the Artifact and Cost

One-sentence takeaway

Tarun122 says they used a large prompt in OpenCode to have DeepSeek V4.1 Flash generate a playable browser tactical shooter in about ten minutes, at a total cost of approximately $0.28 and roughly 300k tokens; the public demo page and code repository support the claim that the artifact exists, but the original post provides no complete prompt, configuration, execution logs, or baseline. This is therefore a personal field report with a public result, rather than a controlled evaluation.

Use cases

• Tasks it is suitable for assessing: Quickly generating a browser game prototype from natural language, combining basic gameplay, and producing a demonstrable finished product.

• Tasks it is unsuitable for extrapolating to: General programming accuracy, success rates on complex projects, cost stability, and fair comparisons with other models.

• Applicable model version: The original post explicitly identifies DeepSeek V4.1 Flash; the API ID, provider, and specific build are not stated.

• Test environment or client: OpenCode; the operating system, initial project state, and tool configuration are not stated.

• Reasoning tier and parameters: Not stated.

Evaluation method

The author first used the model for several tasks in a startup project and then proposed a browser game idea; only an overview of a large initial prompt was made public. The original wording says “Something like,” so it is not a verbatim prompt. The author says the model completed the game after running for about ten minutes. There was no task set, repeated runs, acceptance criteria, independent verification, or control group; “one-shotted” is the author’s summary of this result.

Key results

The author describes a finished product with three guns, including a sniper rifle that can aim down sights with the right mouse button, along with headshot multipliers, recoil, spread, and reloading. The enemies seek cover, perform sprint jumps, or ambush the player; the author also says they can identify an enemy behind them from footsteps. The public demo page shows the VALO ARENA browser tactical FPS prototype, with Quick Match, Endless, three weapons, aiming, reloading, and footstep/gunshot cues. The public repository README describes it as a Three.js + Vite prototype and lists hitscan, headshot damage, sound-driven perception, and a minimap.

Raw data

Conclusions and limitations

This evidence supports the claim that “V4.1 Flash can produce a publicly playable browser game prototype at low cost and in a short time.” It does not support the claim that “any game can be completed in one shot,” that $0.28 is a generally applicable cost, or any performance ranking against other models. The demo page and README verify the result, but they are not a complete record of the author’s execution; comments only joked, in reference to the title, that the author was also defeated in the game, and cannot change the evaluation conclusion.

Reproduction notes

The demo page can be accessed to inspect its features, and the repository README and file structure can be reviewed. To reproduce the result, fix OpenCode, the model version, reasoning parameters, initial directory, and complete prompt; record token usage, billing, elapsed time, build logs, and manual acceptance items; then repeat the run against at least one baseline. The current materials lack these conditions, so comprehensive reproducibility cannot be claimed.