A fun game but time-consuming.
The difficulty level is quite easy. Nearly Headless Nick will guide you around so just follow him or head towards the large arrow. You won't be running around completely lost in this game! Boss fights are easy and in general it takes about 20 minutes to complete a level in story mode when you try to collect all the items. Obviously the game is very suitable for children, but it's also great for adults who want to play a relaxed and fun game for a change. Ya know, like when you need a break from an intense Killzone session ;-)
In order to complete the game you'll have a LOT of collecting to do. This is where it gets repetitive and I can imagine that not everyone feels like replaying levels over and over again to collect all the items. The collectables are:
Studs
Studs are absolutely everywhere and you need to collect a certain amount to reach "True Wizard" status for each level. You'll have to zap a lot of enemies and items in order to get these.
House Crests
Each level has 4 parts of the House Crests. So far I found that in story mode you'll typically be able to collect two of them. For the others you'll have to replay the level with different characters and/or new spells.
Gold Bricks
There are a total of 200 Gold Bricks to collect. You get these by completing story levels, achieving True Wizard status, completing the House Crests, taking classes at Hogwarts and saving Students in Peril. More bricks can be attained by playing the bonus levels, buying them at Eeylops Owl Emporium and finding the ones that are hidden inside the levels.
Red Bricks
There are 20 Red Bricks and these are hidden inside the levels. Keep your eyes peeled for owl posts, if you spot one there is a Red Brick somewhere nearby. The Red Bricks unlock special features like stud multipliers or extra hearts.
Character Tokens
In order to unlock all 167 characters, you'll have to find their Character Tokens. Some are hidden, some are rewarded to you. The majority of characters you'll have to purchase at the clothes stores in Diagon Alley, after you found their Character Token.
All-in-all it's a nice game. The only thing that bothered me a bit is that the controls can be a bit difficult to use when controlling a vehicle or a broom. As said the collecting might not be for everyone. Just for playing through the story mode this game is worth it though. For those that enjoy collecting it adds a lot of hours of extra game play.