The Cat Returns is one weird movie. At the same time I did find it enjoyable, largely because of how silly it was, but at the same time when it ended, I wasn't left with that much to take away from it.
A lot of it might be because of its runtime. It's just a bit over an hour long, and so it doesn't spend too much time in the cat kingdom, and a lot of it does feel kinda rushed.
However, with its beautiful animation and entertainment value, it is worth a watch, especially if you're a fan of Whisper of the Heart, a film to which this one is connected to through one particular character.
