The movie's biggest problem: the ending is too easy to predict.
I recently rewatched the movie... OMG, it's worse than I remember. I remember I watched the movie with my sister when we were 15~16, we kind of bored and discussed the ending must be "Oh, it's just a game." And then the movie revealed: it's just a game.
It's freaking boring because the ending is so obvious, I bet 99% saw that coming. When you know it's just a game, you won't worry about the protagonist.