The Unity Global Game Jam, often referred to as the "Unity GGJ," is a special edition of the annual Global Game Jam event that focuses specifically on creating games using the Unity game engine.   The Global Game Jam itself is a worldwide game development event where participants come together to create games in a short period, usually over a weekend.   The Unity Global Game Jam is a part of this larger event but centers on using the Unity engine as the primary tool for game creation.