Google's brand is about fun, not minimalism. You can look at the page and see a pretty standard corporate blog post. But, if you choose to, you can play with the header. It's fun. Try it.
(Actually, the design is pretty minimal. Big block of text that fits on the page without scrolling, and a few pieces of miscellaneous info on the right hand side. There, but not distracting. I can't really complain about the aesthetics of this design.
If you asked a million people what Google was about, if as many as a hundred of them put "fun" ahead of speed and usefulness, I would be very surprised.
This isn't Google Search, it's the Google corporate blog. It's an ad, essentially. Google wants people to associate the brand with fun.
Balls that bounce around is not exactly the end of the world. Yes, you don't like it. Some other people apparently do. You read the article and discussed it anyway :)
(Actually, the design is pretty minimal. Big block of text that fits on the page without scrolling, and a few pieces of miscellaneous info on the right hand side. There, but not distracting. I can't really complain about the aesthetics of this design.