BBC Micro:bit Toothbrush timer project. Create a new project at https://pxt.microbit.org/, choose the javascript tab and paste this code in.

brushTeeth.js

input.onButtonPressed(Button.A, () => {
    music.beginMelody(music.builtInMelody(Melodies.PowerUp), MelodyOptions.Once)
    basic.showNumber(3)
    basic.pause(20)
    basic.showNumber(2)
    basic.pause(20)
    basic.showNumber(1)
    basic.pause(20)
    basic.showString("Go!")
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        # # . . .
        # # . . .
        . . . . .
        . . . . .
        . . . . .
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        . . . . .
        . . . . .
        . . . . .
        # # . . .
        # # . . .
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        . . . # #
        . . . # #
        . . . . .
        . . . . .
        . . . . .
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        . . . . .
        . . . . .
        . . . . .
        . . . # #
        . . . # #
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        . . . . .
        . . . . .
        . . . . .
        . # # # .
        . # # # .
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.JumpUp), MelodyOptions.Once)
    images.createImage(`
        . # # # .
        . # # # .
        . . . . .
        . . . . .
        . . . . .
        `).showImage(0)
    basic.pause(20000)
    music.beginMelody(music.builtInMelody(Melodies.Entertainer), MelodyOptions.Once)
    images.createImage(`
        . # . # .
        . . . . .
        # . . . #
        # # # # #
        . # # # .
        `).showImage(0)
    basic.pause(4000)
    basic.clearScreen()
})