Its different i'll say that. But i like different - same as Mirror's edge.
Put this way, i reckon you wouldn't begrudge forking out for either. Game looks stunning and is ingenious enough to hold my attention thus far (The kids obviously, are lapping it up) Besides, its great now and again to have a change from the normal run-o-the-mill type 'uber' production *cough* no names.... Lot of imagination and creativity on display here - and crucially, a large portion of that translates into the actual player interactivity as well. Which aint no bad thing at all...so far, so good is what i'll say. Try it - Heck, rent it.
Thumbs up to Rare (and btw Valve this week) as per usual...