Space Invaders microbit

SpaceInvadersMicrobit.js

let Bullet: game.LedSprite = null
let Ship: game.LedSprite = null
let Invader: game.LedSprite = null
basic.forever(() => {
    Invader = game.createSprite(Math.random(5), 0)
    Invader.set(LedSpriteProperty.Brightness, 255)
    for (let i = 0; i < 4; i++) {
        Invader.change(LedSpriteProperty.Y, 1)
        basic.pause(2000)


        if (Invader.isTouching(Ship)) {
            Invader.set(LedSpriteProperty.Brightness, 0)
            Ship.set(LedSpriteProperty.Blink, 1)
            basic.pause(5000)
        }
        if (Invader.get(LedSpriteProperty.Y) >= 4) {
            Invader.delete()
        }
    }
})
basic.forever(() => {
    if (input.acceleration(Dimension.X) < 0) {
        Ship.change(LedSpriteProperty.X, -1)
        basic.pause(150)
    }
    if (input.acceleration(Dimension.X) > 0) {
        Ship.change(LedSpriteProperty.X, 1)
        basic.pause(150)
    }
    if (input.buttonIsPressed(Button.A) || input.buttonIsPressed(Button.B)) {
        Bullet = game.createSprite(Ship.get(LedSpriteProperty.X), Ship.get(LedSpriteProperty.Y))
        Bullet.set(LedSpriteProperty.Brightness, 255)
        for (let i = 0; i < 4; i++) {
            Bullet.change(LedSpriteProperty.Y, -1)
            if (Invader.isTouching(Bullet)) {
                Bullet.set(LedSpriteProperty.Brightness, 0)
                Invader.set(LedSpriteProperty.Blink, 3)
                basic.pause(5000)
                Invader.delete()
            }
            basic.pause(500)
            if (Bullet.get(LedSpriteProperty.Y) <= 0) {
                Bullet.set(LedSpriteProperty.Brightness, 0)
            }
        }
    }
})
Ship = game.createSprite(2, 4)
Bullet = game.createSprite(0, 0)
Bullet.set(LedSpriteProperty.Brightness, 0)