AAA game production-Mirror's Edge

I have a assumption from what I've read,
before Mirror's Edge went into production it was said by the lead animator that the game would be a complete failure and wouldn't succeed, a sentence from a review I discovered came to importance, ("Our lead animator, the first time we actually said this to him--what we wanted to do--he said "it'll not work. You can't do it. It'll be crap," Reminisces Mirror's Edge senior producer Owen O'Brien. That confidence disguised as an argument. Its the kind of thing you only hear when things are awesome now-because they were impossible then.) Being a lover of the game I was immediately shocked when I read this on 1up's website.
   Finding this out got me thinking that if this game came out of production and was released it must of proved that it was fully functional and the original concept and core mechanic were a success.

   Mirror's Edge first started development in July/August 2006 from early concept idea according to producer Tom Farrer.

   Mirror's Edge was originally going to be built in the battlefield engine, the engine they used for the battlefield franchise. But the team came to realize there was alot of irritation with the original first person shooter controls and movements inside the world of the game. At first the team experimented with more mechanical actions like ziplines, grappling hooks etc. Not liking this their response was to look at more ways of locomotion within the world.
Working on locomotion and the game also being set in a urban environment DICE developers realized that vehicles had no use in the world because in their words "we needed movement in the vertical plane quite quickly and vehicles don't provide that."
They also made weapons less important as well, I'm guessing because weapons can reduce the speed of movement and movement was one of DICE's key factors while developing the game.

   According to Owen O'Brien the game underwent many pitch meetings because of the game being unique and never done before.
"Oh, but couldn't you have it in 3rd person aswell?" or "Couldn't you put more guns in aswell?" or "Couldn't we have vehicles aswell?"
   I think O'Brien was good to keep the core mechanic and stop the game from leading off to other aspects, but instead DICE stuck to what they'd set out to accomplish.


   The game was released before DICE's Frostbite engine had been completed so instead DICE used Epic's Unreal engine 3. Aswell a light system known as Beast was created specifically for the Unreal engine by illuminate labs who were in association with DICE.
The brand new software would make the unique art style of Mirror's Edge more noticeable by letting colours reflect as well as light sources.