Harry Potter And The Philosopher's Stone (or Sorcerer's Stone, if you're in the US) is the first piece of the Harry Potter series, and this movie tie-in game loosely follows the story of the book and movie, surprisingly becoming one of the best-selling PS1 games in the process.
Unlike the movie or books, though, Harry Potter also has the additional magic powers of walking through walls and blatantly ignoring people, as well as skipping half of his own game in order to finish the game in a magical 1:13:57.