I liked how well the use of the theme of time fit in with the theme of delivering mail. It was also kind of neat to have to maneuver around the other cats too, which adds a bit of franticness to get to each location in time. Everything I would suggest for this game had already been suggested by the other commentators, so I'll leave it out of my comment!
All in all I thought this game had a lot of potential! It's very cute!