Yes, I'm on a small grid, so only see a "chain" of the boxes being uncovered one by one. It does feel pretty slow, even though I'm nowhere close to speed solving : - )
I've thought about what you said a bit more, and I think you meant it should accelerate with time?
In any case, I've just done that and deployed it. So if you refresh the page, the animation should - hopefully - be less bland. Feel free to let me know what you think.