It was an interesting film, and I did think the twist of the Autistics' ability at maths being the one thing that could save them a good one, but it just never really caught my attention, I think I'd figured out that the Policeman was the bad guy pretty early, but then I was going a spate of watching phsychological horrors at the time, so maybe I was just 'bloated' on them by the time I got to this one.
I may give it another try at some point, but the film didn't really leave me feeling like 'Gosh, what an amazing twist'.
Also Rainman was quite a big film when this came out, so the minute maths was involved, we just knew that something like that would happen.