Harry Potter and the Half-Blood Prince for Nintendo DS features an expansive gameplay experience diverging from a direct movie adaptation. Players control Harry as he navigates Hogwarts, undertaking various side quests, interacting with characters, and solving challenges. The open-world design allows exploration and quest activation through dialogue or cutscenes, with a Remembrall log to track objectives and character locations.
The PSP and NDS versions are not a direct, linear adaptation of the movie, but instead take the player through a larger universe of the series, with many unrelated characters and tasks, eventually furthering the story through cutscenes. At Hogwarts, Harry, the sole character controlled by the player, has to perform many quests for other students, such as stopping bullies, collecting ingredients, or even finding back Luna's accessories that have disappeared. Hogwarts can be explored freely and quests are triggered through cutscenes or by talking to other characters. These are stored in a Remembrall log, where names or characters can be highlighted to find their location on the map.