Under construction/404 Pong SVG animation

Experimenting with "CALLBACKS & PROMISES" in animejs.
Was super fun animating this one!
In this "under construction/404 page" animation concept I'm using multiple timeline animations and those 2 cool functions:
changeBegin() callback is triggered every time the animation starts changing.
changeComplete() - callback is triggered every time the animation stops changing.
check out the codepen:
https://codepen.io/Ilyatsuprun/full/xxKrMWw