Motion is a sentence, not a flourish

Every animation in a product is making a small promise about what's about to happen. If it isn't, it shouldn't be there.

The good rule: motion should help the user understand cause and effect — what they did, what changed, where something went. If it doesn't do one of those, it's decoration, and decoration in a busy interface adds up to noise.

The honest test

Disable the animation. Does the interface get worse to use, or just less fun to watch? If it's the second one, you can probably cut it.