I am a big Harry Potter fan, but this game really doesn't do it for me and this is why.
There seems to be a poorly done cut-scene every couple of minutes in this game. The voices are often out of sync with the animations and the character models show about as much expression as a plank of wood.
Another thing I really hate about these scenes is the lack of characters they put in them, making Hogwarts look like a ghost castle. I almost wonder why they don't just put in out-takes from the actual movie, like they did with the LoTR games. Would save them a lot of time in most cases.
These scenes are also extremely minimal, despite there being many of them, so that if you haven't read the books or seen the movie you will have absoloutely no clue what is going on.
The game just seems to jump around from one cut-scene to another, with small amounts of player input in between. There is no sense of having a free roaming world like there was previous games. Where you would do all the quests available that day, then have the option to "Sleep" to take you to the next day, or run around exploring and doing side quests. It's just "Cut-scene, Potions, Cut-scene, run, Cut-scene, Quidditch, Cut-scene, run, Cut-scene, Duel, run, Cut-scene... etc, etc"
The Potions mini-game can actually get quite frustrating. When you are trying to drop small things into the cauldron, such as a "Rat's Spleen", I sometimes found it quite hard to actually see where it was going to fall. This is really annoying because they make you drop items like this in sometimes 20+ times, ONE AT A TIME, to make a single potion. Apart from that this mini-game is quite fun, but the problem is... It isn't that "mini", you are mixing potions all the time and it's one of the main parts of the gameplay. Gets quite repetitive and boring after awhile.
Quidditch is by the far the stupidest and most pointless part of this game. It requires literally no input from the player, this is not a joke. Once a Quidditch match or practice starts, you can take your hand completely off the controls and just watch. Apart from the occasional bump into a goal post Harry will fly through all the rings without you directing him at all, and catch the snitch himself. Ginny also comes in at random times, flying in front of you, often she is right on top of the snitch. Although having said all that, it does look absoloutely fantastic!
Dueling is basically just a spam-fest. Just keep clicking away with the same spell, whilst moving around in a circle and you will win. When you do win, your oppenent, no matter who he is, always collapses in exactly the same way. This is also very annoying, they could have come up with a bit of variety.
Nearly Headless Nick is seriously over used in this game. If ever you don't know where you're going (which happens quite a bit because NPC's are very vague about quests), press hit "N" and Nearly Headless Nick will pop up out of no where and lead you to where you need to go. I like Nick as a character, but honestly... He doesn't need to hold Harrys hand like that all the time.
The only good thing about the game is being able to run around Hogwarts castle and grounds. Lots of the painting are animated, there is nice Hogwartsy music, a fair number of students walking about, even if a lot of them are clones. It is fun to explore the areas that just don't turn up in the movie.
But again there are some issues with this. Controlling Harry can be very clunky and annoying at times, especially in tight spaces. Also when you have companions following you, like Ron, I find that they are often getting in the way. Especially if you are trying to backtrack.
The graphics certainly aren't as good as I thought they would be, on "High" and 1920 x 1080, some things still look pretty poor and the overall quality isn't as high as I would have expected. The character models in particular are quite poor. Ron's has been done fairly well, but Hermoine and Harry just don't look quite right. Snape looks AWFUL and the hands on all the characters look very amateurish.
The voice acting is also pretty terrible. Harry and Ron I assume are done by Rupert and Daniel, though it's kind of hard to tell. In a few of the cut-scenes I would have sworn it was other people doing their voices, but it's pretty hard to tell because there is little to no feeling put into their lines. This makes the cut-scenes very dull and again I don't know why they didn't just take scenes directly from the movie.
I wouldn't recommend buying this game. EA have really screwed up this series. The games should be getting more mature like the books did as they progressed, not less. If you are a fan of Harry Potter you might want to rent it like I did, you will probably finish it overnight anyway.