Then I saw the film and thought 'I like it, but it's really not all that similar to the game at all'.
Then I replayed Silent Hill 1 just recently and as I was playing kept going 'oh! That's in the film! I forget that was in this too!'...and I realised there were a lot of moments in the film that were actually from the original game and I'd just forgotten about it. This included even tiny details, like camera/shot angles.
I think the biggest one for me was...
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...the barbed wire corpse in the last toilet in the school...I had completely forgotten that was in the game!