I felt horrible for Toshiaki's assistance -_- She was in love with a married man,watch him nearly go insane and then watched him die with his wife in which she obviously envied.They didn't end it the same way the book did though.They found some extra samples of eve in his lab.They burn them though.But someone had to get a hold of one of them for the later incidents in PE2.Sqaure took some imagery from the movie obviously.They even made it so a rat was the first mitocondrian mutation in the game.Th characteristics of Eve changes though.But I was look for something in the book and in the movie to explain why Square took the liberty of making Aya seemingly "immortal".Aya can't age anymore because of her powers.