I finally saw this film as it came free with my housemates newspaper one sunday . I'd played the game before and read the book, but I have to say this was the weirdest film I have ever seen. I don't think it should be dismissed as "sci-fi" nonsense, its interest lies mainly in its character development I would say. It also has a rather serene atmosphere, similar to 2001:A space odessy at times, but more psychedelic. Without spoiling the plot, I will say the effects are dated to the point of humour though, so if you want a good laugh, you can see a fat man fly screaming into the mouth of a giant worm puppet... well... I said it was a weird film...
Edited because of terrible, unforgivable errors grammatical