The Hogwarts Express

This first level is sort of like a tutorial. It is practically the easiest level in the whole game.

After the cut scene go straight along the corridor and cast Alohamora on the door at the end. In the next room Scabbers will cause some luggage to fall over and then Hermione tells you to climb it. You just have to do as she says. The next row of luggage is higher so you just have to jump using the right mouse button. When you jump down you will see some beans. Walk through them and then you will pick them up. You can use the beans to trade for wizard cards e.t.c. at Fred and Georges shop. In the next room you will see a large block with a symbol on it. You will then change characters to Hermione. Throughout the game you will change characters, unfortunately you can't just swap when you like like in the PS2 of Game boy advance. You will then be able to cast Depulso on it which will push it out of the way. At the right at left you will see two chests. Open them with Alohamora and beans will jump out. Keep going across the room. You will see two cages like prisons with padlocks on. Use the Alohamora spell to unlock them. Then you can open the chests inside to get more beans. You can walk into the save book to save your game or just doge it. In the next room you will see Scabbers crawl under a wall. Open the cupboard with Alohamora (you will change to Ron) but make sure that you keep the left mouse button down until you see all three Alohamora symbols appear. Then, when the cupboard is open you can cast Lumos at the Gargoyle and walk through the wall that Scabbers crawled under. When you get into the next room watch out because some pixies will come out! Cast Depulso at them as fast as you can. Then when they are defeated go into the caged off part on the right. Cast Depulso at the symbol and the other caged off part will open. Then you can open the chest that contains beans. Pick up the chocolate frog which will replace any stamina you have lost when you were trying to defeat the pixies. In the next compartment there will be a cut scene where it tells you that you are not really supposed to be in that part of the train. In the next room Malfoy will come in. After the argument, (Lol) Malfoy will show you the monster book of monsters that escapes from the cage and attacks you. Malfoy runs off and leaver you to deal with it. You have to cast Rictusempra at the pages twice but make sure you cast quickly as the first one will make the page come towards you then the second one will destroy it completely. Remember that it's not when all the pages go away (because they wont, they just keep appearing), it's when the books stamina runs out. When the book is defeated it will turn into a wizard card. (Fulbert the Fearful) In the next room (don't worry this is the last part of the level Lol) Harry collapses and the Dementor comes in. Hermione will block the door and go to get help leaving you (Ron) to block the door. Depulso symbols will pop up so you have to quickly cast at them to block the door. But the Dementor still gets through. Then Lupin will appear and Harry will wake up.

I made this walkthrough myself - I hope you find it useful.