Borrowing it
Nothing to install: this file belongs to felipeslo/opencode-kit. 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/felipeslo/opencode-kit/main/.opencode/agents/game-developer.mdgit clone --depth 1 https://github.com/felipeslo/opencode-kitWrote 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/felipeslo/opencode-kit/game-developer)<a href="https://agentmods.dev/agents/felipeslo/opencode-kit/game-developer"><img src="https://agentmods.dev/badge/agents/felipeslo/opencode-kit/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/felipeslo/opencode-kit/game-developer"><img src="https://agentmods.dev/badge/agents/felipeslo/opencode-kit/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 | $0.00059 | $0.01083 |
| Opus 5.5 | $0.00024 | $0.00433 |
| Sonnet 5.5 | $0.00012 | $0.00217 |
| Haiku 4.5 | $0.00006 | $0.00108 |
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
91% identical to game-developer — 13 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 — 164 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 · 164 lines · 59 tokens per session scan A 0fc2a2593358
game-developer is an agent published in the GitHub repository felipeslo/opencode-kit (2 stars, last pushed 7mo ago), licensed MIT. It adds 59 tokens to every session and 1,083 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 91% identical to game-developer, differing in 13 lines, and is treated as a copy.
Other agents, from other repositories
pixel-art-animation-reviewer
Independent reviewer of pixel-art ANIMATION quality (loop seamlessness, motion physics, multi-component motion, frame timing, period selection, particle determinism). One of four specialized review roles in the pixel-art-quality-board orchestrator. Use when the user asks to "check animation timing", "verify loop…
ai-programmer
Implements NPC behavior, navigation, decision systems, and AI support tooling.
console-compliance-reviewer
Reviews console/platform compliance, certification risk, and release checklist coverage.
unity-ui-pro
Build Unity UI — UI Toolkit (UXML/USS/UIDocument) and UGUI (Canvas/RectTransform). Handles screen architecture, data binding, runtime UI performance, gamepad/keyboard input, and cross-platform UI scaling. Use PROACTIVELY for new screens, HUD, menus, in-game dialogs, settings, or any UI work in Unity 2022.3+. Not for…
live-ops-specialist
Specialist for live operations — seasonal events, limited-time content, feature flags, server announcements, update scheduling, and content calendars. Use for planning and implementing live service features.
game-developer
Elite Multi-Platform Game Architect. Expert in game engine internals (Unity, Godot), ECS architecture, real-time performance, and immersive gameplay mechanics. Triggers on game dev, Unity, Godot, shaders, physics, multiplayer, mechanics, graphics.