Sorry for reviving an old thread but I just watched it this morning.
I appreciated it for what it is. Sure, it's not the greatest slasher made but I enjoyed it. Particularly the hot tub scene and the broken glass scene. The killer was obvious from the start but I still thought it was pretty cool. Underrated, IMO.
Valentine was a movie where a hell of a lot of people didn't get who the killer was after seeing it, honestly I don't know how they got so mixed up! The amounts of time I had to explain it to people!
As for the movie, to me it was decent and one of the better slashers that spawned suddenly after Scream.