fyi - there is no checkbox to click on the page, so prepare to be disappointed.
The checkbox shouldn't be any bigger than the "boring" version, and any animation simple and last no more than 0.2 seconds. I really don't like the sound effect used here. If your UI elements are going to make noise when interacted with, I prefer something far more brief and tactile.
watchOS has really satisfying sounds and animations that trigger when you fill your fitness rings and meet goals.
That being said, I think the approach could be really useful for a lot of interfaces. UX design often overlooks the little details that happen when a user interacts with something. A little extra zing can go a long way.