What is unity-video-playtest?

This project is an installable Agent Skill that helps AI coding assistants review animation and motion problems in Unity games. It works with Codex, Claude Code, and Cursor. Instead of relying only on screenshots, which can miss fast motion problems, it records an actual playtest as video and turns that recording into evidence an AI agent can inspect. When you ask the agent to use this skill, it records a specific Unity scene for a set number of seconds, such as watching a character's walk cycle. The skill then checks whether the host AI tool can watch video directly. If it can, it plays the MP4 recording. If it cannot, the skill extracts frames instead, producing a contact sheet image plus a dense set of individual frames around the moment something looks wrong, at a rate of 12 to 30 frames per second. There is also an optional path for tools that already support a generic video watching skill. The output includes the recorded video file, a metadata file, the contact sheet image, a CSV of frame timestamps, and the individual extracted frames. A bundled script called inspect_video.sh can generate an overview of the recording or zoom into a specific time window at a chosen frame rate. The agent then reports findings with exact timestamps, for example noting that a character's sprite snapped forward by a specific number of pixels at a specific moment, and whether the Unity Console logged any related error. The README lists the kinds of problems this is meant to catch: frozen or misordered animation frames, sprite snapping, camera glitches, delayed UI feedback, mistimed particle effects, incorrect draw order during motion, and combat sequencing issues. It captures footage using the project's own camera recorder when available, falling back to Unity's built in Recorder, and finally to a macOS screen capture option if neither is available. The skill requires ffmpeg to be installed. This tool would suit Unity developers who use AI coding agents and want those agents to catch motion and timing bugs that plain screenshots would miss.