Tell us about the features and technologies you used in your Swift playground.

TL;DR, I imported: AppKit, CoreGraphics, GameplayKit, PlaygroundSupport, and SpriteKit.

The main objective for this Playground is to explore the GamePlayKit -- state machines, AI strategies.

This is actually one of the few times I'm using AppKit. I have only programed for macOS twice (when contributing to open source softwares). This is actually the first time ever I really trying to figure out how everything works. For example, it took me a long time to realize I need mouseDown instead of touchesEnded...

There is definitely a lot of places where this Playground can be improved, especially the graphics. For now, the board and pieces are rendered using SpriteKit. In the future, I could extend it to SceneKit (once I take the Computer Graphics class next year , learning about how to make 3D models) and ARKit (once I update my iPad with one having AR capability).