America is the the most productive - and arguably the most gifted - nation on Earth when it comes to making movies. There are countless, superb American films - but the 1990 version of "Lord of the Flies" certainly isn't one of them! Maybe the coming of age genre is not an American strong point (though there are notable exceptions: "Stand By Me" springs to mind). More importantly, "Lord of the Flies" is a quintessentially English story and changing from a preparatory school to a military academy was never going to work. There's something magical about the spontaneity in the 1963 film; the following quotation from an IMDb review seems to sum it up:
What I love most about this cast is that they act like little boys, not little actors, grounding their often awkward actions and behaviors in reality.....
Brook's use of grainy black-and-white photography, plus the lack of any comprehensive musical score (remember Tom Hanks' "Castaway"?), accentuates the bleakness of its surroundings and feelings of isolation......................
By the way, don't waste your time on the 1990 color remake featuring "professionals" like Balthazar Getty. The poetic beauty is all but dissipated in this haphazard, jarringly Americanized update. It makes me worship Peter Brook's version even more.
As for what ended up on the cutting room floor, much still does survive and has found its way into the hands of private collectors. Examples keep coming to light (such as the added bonus material for the forthcoming Blu-ray). The movie was heavily edited, for various reasons, before it reached the cinema. A "director's cut" edition would certainly be of interest to many RFF members were it ever to become available.