The fourth game of Harry Potter released by EA games has great graphics, great sound and is incredibly easy to play.
It's true that the graphics are stunning, the characters have better design and don't look anymore like paper-dolls. The environments are pretty well created, if just have some minor errors at some points; the storyline is something that's worth watching (and playing), because despite it isn't at all exactly developed as the ploy stated in the book or the movie, it makes a fine addition to the HP universe, making the game a good stand-alone in that area.
But nothing is perfect and this game is no exception: the game is too easy, and once you learn to manage the controls, there's no further mind-challenging work left on the game. I think that it is ok for Harry Potter die-hard fans (as me), and children, which is great, because it's one of the few games that I absolutely recommend for little people, since as I said, it's easy and entertaining for them.