This curious piece of animation can be used as a true example of what type of work can be separated of its original genre or even origin. Cat Soup! (Nekojiru-su in japanese) more than a true anime can be considered a weird conceptual animation or may I say, a true piece of art. Based on the surrealistic works of the manga creator "Nekojiru" (who would committed suicide in the middle 90's) it's a different kind of animation, no matter from which perspective do you see it.
So yes it has a history, it has characters and flows like a short film, but as a movie that mostly deals with death, extreme symbolisms and shocking imaginary it's just something hard to explain or look to interpretations. It's also incredibly shocking and although it may look for kids (I mean the story it's center about two cute kittens) its certainly not for every public: entirely mute (the kind of dialogs are in baloon comic style) and the symbolims that deals with death, spiritualism and the grotesque (literally you have a pig eaten himself, a interpretation of the time that changes the concept of "weird", a surrealistic version of god and dead...) will leave you with mix feeelings.
It's without a doubt a masterpice presented in a piece of pure art, so much in fact that in may personal rate I can't even considered it an anime or a regular animation but certainly a "must" for people who are looking something different... very different.
RATE: Personally 4 stars easily. May be worth it half a star less since as said before, not for everyone and certainly not for kids (seriously, can be really disturbing).