Harry Potter and the Half-Blood Prince is based on the movie of the same name. The player takes the role of Harry Potter who has to fight against Lord Voldemort and his minions.
The game allows for some freedom, as between chapters, Harry can explore the school at his own pace. He can use portraits unlocked during the course of the game to teleport instantly to another place or call a ghost to show him the fastest way to the next mission. Exploration has mostly one goal: finding the 150 hidden crests which unlock achievements and trophies.
Exploration is made more manageable by Harry's lack of jumping ability, so he must use spells to reach the hidden crests.
The player will spend most of his time in three mini games: magic duels, brewing potions, and quidditch. Magic duels allow Harry to learn new spells or improve existing ones by facing other magicians and using his spells to defeat them.
Quidditch is a reaction test where Harry's broom flies automatically and the player can only slightly move it to fly through rings or avoid obstacles. Brewing potions requires recreating a recipe by using ingredients in the correct order on a bowl, with added challenges such as heating up the bowl or stirring the brew.
Harry Potter and the Half-Blood Prince was released for the Playstation 2 on June 30th, 2009.