Very nice demonstration of animation principles for exaggerated motion. I would, however, hesitate to use this type of animation by default and certainly not for this particular application. In this example, something that should most likely be taken seriously (identity and authentication) has been made whimsical. While it’s great to have the ability to do something, exercising restraint may be even more important.
It is nice to see that we’re finally back to the level of animation possible with Flash in 2004, so there is that.