This was fun. I liked the interplay between Emmy and her various friends, rodent and human. They were all vivid characters in their various ways, and different one from the other - the narcoleptic professor and the sweet gentle Endearmouse and the vainglorious Shrinking Rat and the popular jock who joins the doormouse soccer team.
The villainous nanny is suitably villainous and doesn't have a change of heart or get revealed to be just misunderstood but stays a thoroughgoing villain right through her comeuppance. Which I appreciate very much. I want my villains to be villains otherwise where's the triumph in overcoming them?