From a development point of view, Harry Potter and the Deathly Hallows Part 1 is the story of trying to cater to at least two entirely different groups simultaneously. While officially it's been built for pre-teen boys and is pegged as a kind of introductory shooter, it's also been developed as a bit of an evolution for the series. It takes its cues from the book and movie; Hogwarts has been replaced with a moss-and-concrete English setting, Harry is on the run from the Ministry of Magic, and the guy is sporting some hefty "childhood-be-gone" stubble. Stuck somewhere between childhood and adulthood he's actually surprisingly representative of the game which seems to have been built to bridge that awkward and often frustrating gap between young and old, casual and hardcore gamer.
The problem, however, stems back to the book. The novels had grabbed the attention of a full spectrum of readers. I remember the days when I'd spend at least ten minutes of my bus journey trying to count how many business women were working through a copy of Potter. It had universal appeal despite the fact that it was first and foremost a children's novel.
Now the kids who treated the series like it was Beatlemania have grown up and probably become acquainted with console gaming along the way. But for the rest of the leftover Potter fans, it's unlikely they've been swallowed up by gaming culture in the same way. The new generation are unlikely to have learned the traditional controls of shooters. So Deathly Hallows Part 1 attempts to set up the building blocks of the genre instead, taking what was a basic kids' game and transplanting it to a mature genre - then distilling that genre to be accessible to kids and casual players.
In the level I was shown Harry is on his own at the centre of the building of Ministry of Magic, in what is basically a faceless grey maze of corridors which are patrolled by various enemies. So immediately you're faced with two ways of dealing with the level: you can fight your way through it or pull on your invisibility cloak to stealth your way through the level.
The cloak system looks to be one of the more polished aspects at this stage, partly because it's nice to see a traditional gaming conceit like stealth being so well integrated with such a recognisable technology from the novels. So in standard stealth style the faster you move, the closer you get to people, the more noise you make, the more you burn through your ability to stay hidden - stand still and it will regenerate. Get close enough to the enemy and you can stun them.