Based on Unreal Engine 3, with PS3 allegedly lead platform Mirror's Edge is an ambitious attempt at merging Parkour, stealth and more traditional FPS elements into one glorious whole. It's like a more stylised, first person perspective Assassin's Creed, but without all the free-running bits done for you automatically. This seems to have attracted criticism in that the control system is rather complex, but I rather like the freedom the game affords you.
A quick analysis of the demo reveals that in common with most UE3 titles, Xbox 360 still holds the technical edge, but PS3 manages to hold its own. Both PS3 and 360 versions have their fair share of 'jaggies', but the overall experience is a little smoother on the Microsoft console, thanks to the inclusion of selective 2x multisampling anti-aliasing (MSAA).
