A swift playground with rotating, translucent squares

CCRotatingSquares.swift

import SpriteKit
import PlaygroundSupport

let view = SKView()
let scene = SKScene(size: CGSize(width: 100, height: 100))
scene.backgroundColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
scene.scaleMode = .aspectFit

for i in 1 ... 7 {
    let rect = SKShapeNode(rect: CGRect(x: -25, y: -25, width: 50, height: 50))
    rect.position = CGPoint(x: 50, y: 50)
    
    rect.fillColor = #colorLiteral(red: 0.5725490196078431, green: 0.0, blue: 0.23137254901960785, alpha: 1.0)
    rect.alpha = 0.2
    rect.lineWidth = 0
    
    let time = pow(0.8, Double(i)) + 0.2
    
    let rotate = SKAction.rotate(byAngle: 1, duration: time)
    rect.run(SKAction.repeatForever(rotate))
    scene.addChild(rect)
}

view.presentScene(scene)

PlaygroundPage.current.liveView = view
PlaygroundPage.current.wantsFullScreenLiveView