Citrus Engine is a 2D game framework for ActionScript 3 that simplifies the development of physics-based games, especially platformers. Built on top of Starling and Box2D, it provides a component-based architecture and high-level abstractions for objects, input, levels, and camera control. It’s well-suited for educational games, side-scrollers, and mobile game development using Adobe AIR.
A free ActionScript 3 library designed for developing 2D Flash games
FlashPunk is an open-source 2D game engine for Flash, designed for rapid game prototyping and development in ActionScript 3. It offers a simple entity-component system, support for tilemaps, collision detection, and animation, making it ideal for creating pixel-art and arcade-style games. FlashPunk was a favorite among indie developers in the early 2010s due to its simplicity and performance.