Pleasingly faithful to the book, and seemingly heavily inspired by the film (the sets look like the film, as do the avatars, and the voices & music also sound like the film). Anyway, it's a thid-person perspective 3D game (like Tomb Raider, although a less impressive graphics engine) where you explore Hogwarts, learning spells solving puzzles, attending classes and so on. They also have some great sub-games - like Quidditch and a mine-cart type game from Gringotts.
It's extremely easy (I'd finished over 80% of the game in about 6 hours), and with infinite continues when you die (itself no mean feat - the game goes out of it's way to give you more energy!). The controls are dead-simple, although some co-ordination is required with some of the spells - I guess it's really aimed at Potterphiles, ie pre-teens.
All this said, I really enjoyed it, and I'm sure any 10 year old would love it, even if it hasn't got the long-lasting appeal of, say, Sypro. Worth hiring.. might be worth buying if it comes out in a budget range.