The procedure of creating the Mirror’s Edge map editor is complicated, though: you have to copy some Unreal Tournament 3 editor files into the installation directory of the game, which might be considered hacking, since it’s not approved by Epic or Mirror’s Edge’s developers. But the results are there if you are willing to take the risk: there are already reports of brand new Mirror’s Edge maps out in the wild. However, make sure that, if you start playing hackers, you are ready to deal with the possibility of doing some damage to your game. You never know, right?
However, if you are ready to do it and you think you’ve got the skills, maybe this little link might help you. Maybe somebody will tell you how to do that too.