This is, for lack of a better term, an art film. This should be said from the start, because while many of Oshii's anime films are of a philosophical bent, they hew closely enough to convention to appeal to mainstream movie fans. This film probably does not.
Judging the film as a whole, it makes some interesting philosophical points and pays off at the end. The question is whether this payoff is enough to justify what went before. I am not sure about this.
Normally one assesses a confusing film that can only be fully grasped at the end by looking at that film's secondary characteristics.
Judged as an art film, the movie's technique is expert, but it is not so innovative or visually compelling so as to justify the film by itself. There is nothing wrong with the acting in this movie, but it is not so compelling that it shifts one's focus from the film as a whole.
Judged as a more commercial or mainstream film, this movie is distinctive for its emphasis on humor. That humor is an old-fashioned form of slapstick however, and while this will make the film for some people, if you do not especially like this form of humor, then the fact that it is placed in a confusing and rather dark movie will prevent the individual bits of humor from coalescing into a funny unity greater than the sum of the parts.
The one thing that cannot be denied or dismissed, is that this film is an original one, and is philosophical without being preachy. If this is enough, then you are certain to be satisfied.