I must say that when I first saw and played the game, I was also taken aback a tad by the athleticism of the player character. But trust me when I say that you get used to it very quickly and soon start to appreciate and enjoy the freedom - and possibilities - it brings. Now I'm of course so familiarised with it that the lack of this feature annoys me in other 1st/3rd person RPG games. The being rooted to the ground in Fable is one example.
I am in blood Stepp'd in so far, that, should I wade no more, Returning were as tedious as go o'er.