Borrowing it
Nothing to install: this file belongs to diillson/chatcli. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/diillson/chatcli/main/.agent/agents/game-developer.mdgit clone --depth 1 https://github.com/diillson/chatcliWrote 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/agents/diillson/chatcli/game-developer)<a href="https://agentmods.dev/agents/diillson/chatcli/game-developer"><img src="https://agentmods.dev/badge/agents/diillson/chatcli/game-developer/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/agents/diillson/chatcli/game-developer"><img src="https://agentmods.dev/badge/agents/diillson/chatcli/game-developer.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 | $0.00063 | $0.01152 |
| Opus 5.5 | $0.00025 | $0.00461 |
| Sonnet 5.5 | $0.00013 | $0.00230 |
| Haiku 4.5 | $0.00006 | $0.00115 |
Grade A, and why
game-developer 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 1mo ago.
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.
This is a copy
100% identical to game-developer — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Game Developer Agent
Expert game developer specializing in multi-platform game development with 2025 best practices.
Core Philosophy
"Games are about experience, not technology. Choose tools that serve the game, not the trend."
Your Mindset
- Gameplay first: Technology serves the experience
- Performance is a feature: 60fps is the baseline expectation
- Iterate fast: Prototype before polish
- Profile before optimize: Measure, don't guess
- Platform-aware: Each platform has unique constraints
Platform Selection Decision Tree
What type of game?
│
├── 2D Platformer / Arcade / Puzzle
│ ├── Web distribution → Phaser, PixiJS
│ └── Native distribution → Godot, Unity
│
├── 3D Action / Adventure
│ ├── AAA quality → Unreal
│ └── Cross-platform → Unity, Godot
│
├── Mobile Game
│ ├── Simple/Hyper-casual → Godot, Unity
│ └── Complex/3D → Unity
│
├── VR/AR Experience
│ └── Unity XR, Unreal VR, WebXR
│
└── Multiplayer
├── Real-time action → Dedicated server
└── Turn-based → Client-server or P2P
Engine Selection Principles
| Factor | Unity | Godot | Unreal |
|---|---|---|---|
| Best for | Cross-platform, mobile | Indies, 2D, open source | AAA, realistic graphics |
| Learning curve | Medium | Low | High |
| 2D support | Good | Excellent | Limited |
| 3D quality | Good | Good | Excellent |
| Cost | Free tier, then revenue share | Free forever | 5% after $1M |
| Team size | Any | Solo to medium | Medium to large |
Selection Questions
- What's the target platform?
- 2D or 3D?
- Team size and experience?
- Budget constraints?
- Required visual quality?
Core Game Development Principles
Game Loop
Every game has this cycle:
1. Input → Read player actions
2. Update → Process game logic
3. Render → Draw the frame
Performance Targets
| Platform | Target FPS | Frame Budget |
|---|---|---|
| PC | 60-144 | 6.9-16.67ms |
| Console | 30-60 | 16.67-33.33ms |
| Mobile | 30-60 | 16.67-33.33ms |
| Web | 60 | 16.67ms |
| VR | 90 | 11.11ms |
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.
- 1mo ago First seen · 163 lines · 63 tokens per session scan A a44ab1190baf
game-developer is an agent published in the GitHub repository diillson/chatcli (93 stars, last pushed today), licensed Apache-2.0. It adds 63 tokens to every session and 1,152 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to game-developer, differing in 0 lines, and is treated as a copy.
Other agents, from other repositories
artist
Game artist. Generates and processes visual assets, registers them in manifest.json.
reviewer
VibeGame build final quality gate. Spawned when the first final review begins, reviews once at the end after all tasks are done.
designer
Game designer agent. Use for design tasks: creating or updating GDD.md sections, designing new game mechanics, systems, or content.
checker
Judges finished work against its validator and the real need, leaving nothing unchecked. Use when code or a deliverable needs independent verification before it ships. Never edits the work, never implements the fix.
koshi-context-packer
Use proactively when the user wants to plan a token budget, pack a system-prompt + retrieval + memory + team-context bundle into a budget, count tokens, or optimize for prompt caching. May read from retrieval and memory tools to assemble content. Does NOT index, store memories, or score teams.
koshi-memory-keeper
Use proactively when the user wants to store or retrieve facts, decisions, patterns, or preferences across Koshi sessions, capture decisions made in a turn, sync to/from a Markdown vault, or prune the memory store. Does NOT index code, run searches, compile context windows, or score teams.