First off, the presentation for this is incredible. Great, consistent graphics and sounds, and fantastic animations.
The gameplay loop is also pretty good, and I loved how you introduced it first as a normal pest killing game and then swapped the roles; very cool. I was immediately killed in the first level, because it wasn't obvious to me that the game had started already. The level name is "The basics" or something, so I thought this was still an explanation. Maybe having some sort of "start" or "go" message would have helped note that this is the start of the gameplay? Though it's a very minor gripe.