Harry Potter and the Half-Blood Prince Quiz

Answer: The Burrow

The game begins with Snape taking part in a vow: watch over Malfoy and provide assistance if he can't fulfill the goal Voldemort set for him. After that scene, Harry arrives at the Burrow, which is where the player takes control of him. Ginny and Hermione each have a task for Harry that functions as a tutorial for the game. Ginny helps Harry with his flying, since he has just been made captain of the Gryffindor Quidditch team.

Hermione asks Harry to help clean out Fred and George's cauldrons.

This is accomplished by using the spell Wingardium Leviosa to levitate the cauldrons into a nearby pond.

Answer: Duelling Club

Dumbledore reinstates the Duelling Club (originally from "Harry Potter and the Chamber of Secrets") in order to prepare students, since dark forces are at work now that Voldemort has no reason to stay hidden.
Harry's first duelling match is after his first Potions lesson in the Great Hall against Ron. He teaches the on-looking students the stunning spell, Stupefy.
He also has duelling matches against a Hufflepuff, Ravenclaw, and Slytherin student. Each time Harry gains access to a new spell. Harry encounters the Hufflepuff student while heading to his first Quidditch match, the Ravenclaw student while heading to the second Quidditch match, and the Slytherin student while heading to Potions class after the second Quidditch match.
Once Harry becomes victorious against each opponent, he is a member of that house's dueling club and can practice his dueling against tougher opponents.
Apart from these official duels, there are other times in which Crabbe and Goyle ambush Harry and he must defend himself, one of which is while Harry has taken Felix Felicis, and since it is a luck potion, it is impossible for Harry to lose. All of Harry's spells get magnified and any spell Crabbe and Goyle fire at Harry doesn't affect him in the slightest.

Answer: Light fireworks

Harry decides to ask Luna Lovegod to the Christmas party, but before they can go to Slughorn's office, Luna must first light fireworks to alert people that there's a party. Harry accomplishes this by using the spell Incendio on the boxes of fireworks. These boxes can be found from Luna's starting position at the boathouse all the way to the doors that lead to the Viaduct Entrance.

Answer: Harry must begin his spying again.

During Slughorn's Christmas party, Snape wishes to talk with Malfoy, who crashes the party. Snape takes Malfoy to the seventh floor, and Harry decides to follow the two of them to figure out what they are talking about. If Harry gets too close, then Snape berates Harry and the spying portion of the game must begin again. The same thing happens if Harry gets too far away from them (obviously excluding the berating part).
Snape and Malfoy are discussing Snape's offer to help Malfoy and the latter's sloppiness in trying to fulfill the goal Voldemort set for him.
Later in the game, Harry chases Malfoy from the Great Hall to a restroom. Once again, Harry must avoid being too close to or too far away from Malfoy.

Answer: Uses Lavender's bag to capture the books

Lavender is in love with Ron, who does not reciprocate the feelings. Therefore, when Harry and Ron notice Lavender trying to catch her books, Ron asks Harry to get rid of Lavender being she notices him. Harry does this by helping Lavender catch her books by using her bag to capture them. Harry uses the levitation spell on her bag and then moves it around to where the books are flying, so the books fly into the bag. Once inside the bag, the flying books no longer fly and therefore do not try to escape. Afterwards, Harry turns Lavender that Ron is in the Divination tower.

She finds this strange as Ron doesn't take Divination nor does he like the subject. Harry explains that Ron wishes to know his future, and Lavender assumes by "future", he means his and Lavender's future.

She leaves for the Divination tower and Harry and Ron are free to head to Potions class.

Answer: Astronomy Tower

Harry is told that Professor McGonagall wishes to see him at the Astronomy Tower, which Harry finds suspicious for two reasons: 1) the student is a Slytherin, and Slytherins are rivals to Gryffindors, something that Professor McGonagall knows and 2) Aurors (dark wizard catchers) have shut the Astronomy Tower for the time being. Nevertheless, Harry goes up there and finds that it's a trap set by Malfoy, who was the one who sent the message. Harry finds Malfoy's friends, Crabbe and Goyle, up there and must fight them. Once Harry wins the duel, Crabbe and Goyle lock Harry in the Astronomy Tower. To escape, Harry must levitate a key underneath the portcullis and into a keyhole, which will open the portcullis.

Answer: Ron

Ron eats a box of chocolates not realizing that they contain a love potion. Harry decides to ask Professor Slughorn for help. On the way from the Gryffindor common room to the Potions classroom, the player is in control of Ron, who follows Harry to the destination.

While playing as Ron, Lavender Brown encounters the two of them. Ron explains he is going to see Romilda Vane (the person who added love potion to the chocolate) which confuses Lavender as she believes Ron is in love with her. Control returns to Harry in Slughorn's office when he makes his potion for Ron. The player can also play as Ginny during the third and final Quidditch match. Harry has received detention from Professor Snape and can't play, so it's up to Ginny. Despite this change of players, the goal (to fly through enough stars in order to better capture the Golden Snitch) remains the same as previous Quidditch games and practices.

Answer: Felix Felicis

Harry's first class after term begins is potions taught by Professor Slughorn. For this lesson, Harry must brew the Wit-Sharpening potion. The ingredients are already provided for Harry and all he needs to do is move them from the desk to the cauldron and pour. If he pours too much, then smoke will appear and he will have to redo that ingredient.
After the first Quidditch practice, Harry meets up with Ginny who informs him that she has to create the Shrinking Solution and write two essays. Harry offers to brew that potion for her. Harry heads to the Herbology greenhouse to do so, but before he can, a student informs him that he must join the Potions club. In order to join, Harry must brew the Volubilis potion. Once he does that, he can make Ginny's potion.
After Christmas break, Harry trails Malfoy but eventually loses him. All that is left is a list of potion ingredients. Harry heads to the Potions classroom to brew the potion to figure out what it is. Professor Slughorn compliments him on an excellently brewed Polyjuice Potion.
Harry does use Felix Felicis during the game but he does not have to brew it; rather, he is awarded it by Professor Slughorn.
Other potions Harry must brew include Wiggenwald potion (which differs from how it was brewed in "Harry Potter and the Chamber of Secrets"), an elixir to induce euphoria, an antidote for a love potion, and fertilizer. When brewing fertilizer, Harry has taken Felix Felicis, a luck potion, and therefore it is impossible to mess it up. Although not technically a potion, Harry does make some punch for Slughorn's Christmas party, which is done in the same manner that Harry brews potions.

Answer: Alohomora

Harry learns many spells during the game:
1) Petrificus Totalus, a paralyzing spell - Harry learns this spell during his duel with the captain of the Slytherin Quidditch team
2) Expelliarmus, a disarming spell - Harry learns this spell during his first duel, the one in the Great Hall with Ron
3) Levicorpus, raises an enemy in the air - Harry learns it during his duel with the captain of the Ravenclaw Dueling Club. After learning this spell, duels become more easier to win.

Other spells Harry learns include Protego (casts a barrier around Harry to protect him for an opponent's spells), Stupefy (stunning spell), Wingardium Leviosa (levitation spell), Reparo (repairs an object), Incendio (lights an object on fire), Accio (summoning spell), and Depulso (pushes objects away).

Answer: He earns a full-sized challenge crest.

There are 150 challenge crests in the game. There are 125 full-sized crests somewhere around the castle; the other 25 Harry can earn if he has 100 mini challenge crests. These crests can be out in the open, placed on the walls, behind locked places (which requires Harry to levitate the crests), and hidden inside or behind objects.

There are even some that are broken, in which case, Harry needs to repair them using the spell Reparo. Others are on a lion statue and can only be collected if Harry performs a task, such as making a potion or duelling a student.