With PoP, it works because even when your next course of action isn't blindingly obvious (Hey, another series of pillars that I can grab on to - I wonder if I should grab on?) and the path isn't totally linear (which happened quite a bit), there's little consequence to

ing up. Come into a room. Run. Jump. Fall... rewind, run slightly differently, jump and move on. Without that, you have to slow down. Which is totally fine... if you're playing Metroid Prime. But from what I gather, much of the fun of Mirror's Edge comes from the speed at which you're moving. Hell, without proper momentum, getting across a lot of things just isn't possible. Having to stop and reorient yourself every time you pass an obstacle just ain't how you're supposed to do it, no matter how realistic it might be.