An AI agent that playtests the game it just built

What it does

OhMyGame is a desktop app (macOS and Windows) that tries to be a whole one-person game studio. You describe a game; the agent drafts the design doc, generates art, video, and rigged 3D models on a shared canvas, writes the code, runs it in a live preview, then opens the game in a window and plays it — including real-time canvas and WebGL games — to check it works. When it finds a problem, it tries a fix and plays again. Finished games publish to a browser-playable link.

The interesting bit

The architecture is refreshingly unmagical: every workspace is just files. Design docs are Markdown, boards share one JSON node model, and playing the game is an ordinary tool call (game_use) next to the coding tools — which is why one agent can chain design, art, code, and playtest in a single conversation. It runs Pi under the hood, with persistent sessions and a GUI built for watching results rather than reading diffs.

Key highlights

• Canvas where design docs, images, video, and 3D models sit side by side; nodes can reference each other, feeding a shared Asset Library
• BYOK across 40+ coding providers (Anthropic, OpenAI, DeepSeek, Qwen, and more), plus media providers for images, video, and 3D
• Can also drive Claude Code, Codex, and OpenCode as coding agents while keeping its own history and canvas
• Three project modes: web games (Three.js/R3F/Phaser), interactive stories as a node graph of playable web pages, and a stack-agnostic General Game mode
• Keys live in a local daemon and never reach the agent’s workspace or your game; Apache 2.0

Caveats

• Explicitly in beta — the README itself says to expect rough edges
• Windows build isn’t code-signed, so expect a SmartScreen warning
• Playtesting is open-loop: the agent plans a batch of inputs and checks results, no real-time reflexes (per a README comment)

Verdict

Worth a look if you want to prototype browser games or interactive stories with AI and hate juggling six tools. If you need a native-engine pipeline or production polish, this isn’t there yet — and it’s honest about that.