Carpe Retractum:
For advanced spell casters, when you are pulling the control stick in the direction you want to pull, wiggle it around that point. You will find that your Carpe Retractum spell is quicker at pulling. The best place to try this is the Prefect’s Bathroom.
Game play movie:
When the screen telling you to press any key appears, wait for awhile. A game play movie will eventually begin.
Defeating Voldemort:
After the third task, when Harry is alone against Voldemort, you first need to kill all the skeletons, before and after you link wands. When Voldemort is hurling the statue at you, dodge it until it gets stuck in the ground for a few seconds then hit it with the giant ball of light that is coming from the wands. Repeat this until all the limbs are off the statue and you will win.