This film is one of my favourites, out of any I've yet seen.
Why so? Well, to begin with, it's visually a real masterpiece. If you're an artist, or just love beauty, you are very likely to be thrilled by the visuals, which are really very psychedelic!
One of the other reasons I love this film, (and often lend it out) is the central theme concerning life after death. I've worked with a lot of people who are feeling very suicidal, and for many long years have deeply studied the whole topic of life after death.
I've also had some very 'near misses' myself, and gained personal insights...
This film depicts the most 'realistic' appraisal of what heaven (and hell) is like, over and above any other cinematic representation I've yet seen, and so is effectively very 'educational' in that respect. By this I mean that 'hell', or 'Hades' isn't, --to the best of my knowledge-- as many religions indicate, a place of flames and heat, but more often a very chilly, foggy, very lonely sort of place, --more especially for those who've taken their own lives, or have lived very selfish, materialistic lives and / or done much harm to others.
In the same vein, 'Heaven', (aka: 'The Summerlands', the 'Astral Plane', the 'Subtle World' and etc) is well-depicted in this movie, -as being a place where all our thoughts and desires and creations are instantly made into form, -- and the place, or plane, is alive with transcendent colour, (and sounds) far richer and a hundred times more spectacular and breathtaking than anything possible on our much more mundane 'Earth plane'.
Another theme echoed in this film is the notion of: "Omnia vincit amor" (Love conquers all) so our hero (Robin Williams) is, in this movie (if not in any actuality?) able to clamber about in the Lower Spheres in order to find and rescue his beloved wife from the dire fate she bestowed upon herself, -by ending her life too soon; -- { forsooth, the lords of Karma might have a thing or two to say about that! }
The supposed adept, Shakespeare, knew a few secrets about life... and death, and to those familiar with Hamlet, they will recognise the film's title:
"To sleep: perchance to dream: ay, there's the rub;
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil... "
People unacquainted with (and thus ignorant of) the topics of karma, and the continuation of human consciousness after death of the physical body may (and do!) often cynically scoff at the notion that any of this stuff has any bearing on reality, but hey... (as Shakespeare also said) ::
"There's more to heaven and earth Horatio, than this world dreams of!"