The person transformation is ok, but if the transformation is suppose to be quick, they I wonder why the background is changing too. The background changing to me would mean you wanted to speed up the day and night time and the transformation really should have taken several hours.
The rain sound never stops or is out of sycn, and some what annoying while I write this.

:\ crap

Although not the best peice yet, I think you should continue and improve on your skills, you have potential. Keep at it.

Well I don't want to discourage you, but you seem new to animation. How long have you been animating? If you're very new, I say it's a good start, my first animations where worse than this (8 years ago)

This is an amazing mouse transformation, the animation is really good, it's a good work in progress