Invisibility Cloak:
This cloak is not too helpful. Prefects will still catch you. The most you can do is not touch the Prefects. Filch can usually find you, even if you do not touch him. If you do get caught, even without the cloak, you will not get House Points taken away from you.

Hidden items:
Search all of the desks in the classrooms. They contain Beans, Cauldron Cakes, Pumpkin Pasties, Stink Pellets and even Wizard Cards.

Extra Chocolate Frogs with Voldemort:
If you have used the three frogs in the battle before Voldemort (Gytrash), do not worry. You can get these again. Save the game in a safe area in the middle of the battle. Then, exit the game and reload it. The frogs will be there again.

Defeating Trolls:
You have multiple encounters with trolls. Find a Spongify tile and shoot Spongify at it. Wait for the troll to run at you. Then, jump on the tile towards the troll. He will hit the tile then hit himself on the head.

Defeating Venomous Tentecula:
To beat the Tentecula, run back and forth and make him spit poison at you. Use Diffindo to cut off one arm then continue to run back and forth. Cut off the next arm. Immediately cut off the head and shoot Incendio (power up for a few seconds, but not too long or the arms will grow back) at him. You should defeat him in a few shots. There are two Tenteculas.

Defeating Devil's Snare:
The Devil's Snare is exactly like the Tentecula, but much easier. Cut off his arms and his head then shoot Incendio at him. This time do not worry about running back and forth. Stay still and he will not hurt you much.

Defeating the Mutated Gytrash:
When you enter the chamber after the chess board, there will be a short intermission sequence about Professor Quirrel. After that, he releases about six Mutated Gytrash. In order to defeat them, you have to use Lumos (power up, shoot it, then move towards one or more of the Gytrash). Make sure that you are almost touching them. After you have defeated one of them, Quirrel will try to bring it back. Since you cannot hurt Quirrel while the protection (blue wall) is around him, wait until he puts down the protection. Immediately shoot Flipendo to stop him. Be on guard until he puts the protection up again. Then, resume defeating the Gytrash. Watch out for the Gytrash's "echolocation". If it touches you, it will knock you down and stop whatever spell you were performing. The more Gytrash you defeat, the harder it will be to keep up with Quirrel and the other Gytrash