The world presented is post-apocalyptic, with a not so subtle environmental/ecological text.
The eponymous Nausica is a princess of her valley (yes, that's eponymous too - what's the record for a title?) and she's an adventurous sort.
Her valley lives near the deadly poisonous forest, because the wind blows in the right direction. The whole valley society is based on gliders and such. It all looks very very cool.
There's the obligatory empire, big beasties that should not be awakened, and everything comes out right in the end.
The movie feels a bit rushed - but that would be due to the vast amount they had to squash in.
It only follows the plot from the first of the four manga volumes. - MoonShadow
True, otherwise we'd be reprising car-crash jokes. It doesn't strike me as quite as the other car-crash films though. Perhaps a relation? Or perhaps it's more down to the (deliberately) constrained pallette.