Unlike the original, the My Bloody Valentine remake set up a motive for Tom right from the beginning. Between that and his behavior throughout, it came as no surprise that he was disassociating and hallucinating during every murder.
The 2009 version also had the disadvantage of viewers potentially knowing who the killer in the original was and assuming the remake would go in a different direction. All that said, in my opinion, this was one of the better horror remakes of the aughts.
