Short entertainment for HP fans.
The gameplay was interesting. You play as young sorcerer-to-be Harry Potter and naturally, the game features a nice set of spells to be used in various situations. There was some combat, some stealth, some puzzle-solving so it really offered a little of everything. The various levels are filled with several obstacles although they do get repetitive. The castle exploration was really fun (if you enjoyed the books and movies) as well as the possibility to collect wizard cards. The music was also good for a GBA game.
Unfortunately this game suffers from two things. The quidditch game is plain bad. The attempted 3D environment makes it confusing and barely possible to beat even the training session but since this isn't the quidditch cup game, we can forgive that. The game is also incredibly short and you'll find yourself in the final dungeon before you know it.
So it's a nice game if you liked the original story and don't mind playing it on Gameboy Advance. Just remember it won't keep you busy for very long.