That's a really fun, well presented and best of all clear game! It's well telegraphed how to play, and has enough feedback that it's completely obvious how it works. I love the way the premise makes sense too.
It's pretty hard, especially when the rats are against a wall. The dog loses momentum a bit fast when you go out of sight too, which makes it a little frustrating when dodging around things. Also the camera zoom doesn't let you keep track of any rats that are off-screen, so you can run into them a bit easily.
With a few tweaks, there's a lovely little game there! Well done.