Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add krzysztofsurdy/code-virtuoso --skill game-feature-loopgit clone --depth 1 https://github.com/krzysztofsurdy/code-virtuosoWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/krzysztofsurdy/code-virtuoso/game-feature-loop)<a href="https://agentmods.dev/skills/krzysztofsurdy/code-virtuoso/game-feature-loop"><img src="https://agentmods.dev/badge/skills/krzysztofsurdy/code-virtuoso/game-feature-loop/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/krzysztofsurdy/code-virtuoso/game-feature-loop"><img src="https://agentmods.dev/badge/skills/krzysztofsurdy/code-virtuoso/game-feature-loop.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00077 | $0.02489 |
| Opus 5.5 | $0.00031 | $0.00996 |
| Sonnet 5.5 | $0.00015 | $0.00498 |
| Haiku 4.5 | $0.00008 | $0.00249 |
Grade A, and why
game-feature-loop scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Game feature loop
A game can pass every test and still be unplayable: the input is never mapped, the node is not in the scene, the animation fights the movement code. An agent that stacks three features before running the game then cannot tell which one broke it. A screenshot does not settle it either, because a still frame shows layout, not behavior. This playbook builds one mechanic at a time and treats "done" as behavior observed in the running game.
Gates that apply to every step
| Gate | Rule |
|---|---|
| One mechanic at a time | Do not start the next mechanic until this one is proven and committed |
| Done means observed | Tests passing, a clean compile, or a good screenshot is not done. Behavior read from the running game is |
| Two failed fixes | After two failed attempts at the same problem, stop. Report what was tried and what was observed. Do not guess a third time |
| Ask before spending | Paid asset generation (images, 3D, audio, sprites) needs explicit approval and a cost first |
| Ask before scope jumps | A new subsystem, an engine change, or a rewrite of existing architecture needs a yes before any code |
| Art bible first | If the project has an art bible or style guide, follow it. Do not add a new art source or mix styles and resolutions without asking |
| Tests for pure logic only | Test-first applies to damage math, inventory rules, state machine transitions. Gameplay and visuals are checked by running the game |
Step 1: detect the engine and version
Do not assume. Look for the project fingerprint, open the file, and confirm it is a real project root and not a vendored sample or a dependency. Read the version from the project's own version source before choosing any API, because engine APIs differ between major versions and tutorials mix them.
The fingerprints, version sources, and ambiguity rules are in engine-fingerprints. If two engines match (a monorepo), pick by the directory the request is about. If none match and the user named no engine, ask. Never load engine knowledge on a guess.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 133 lines · 77 tokens per session scan A a259ca08e024
game-feature-loop is a skill published in the GitHub repository krzysztofsurdy/code-virtuoso (36 stars, last pushed yesterday), licensed MIT. It adds 77 tokens to every session and 2,489 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-23.
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