Mirror's Edge.
The idea was great, a first-person free-running game. The execution was terrible, the controls were iffy and everything seemed to get samey quickly.
The most immediate fix for the whole thing? Keep the story, if you really want, but drop those horrible cutscenes and make the entire game a sandbox.
That's my biggest problem with that game; it was on rails, it wasn't as free as it could've been. Introduce side-quests involving those yellow back-packs, do jobs with other runner gangs (or against them). Even having races from point a to point b would've been a lot more fun if we got to pick the route. Also, the city felt dead, there was no life other than whoever wanted to kill you, or the scripted NPCs that were there to drive the plot along, there was no-one wondering the streets or going about their lives, so put some of that into it too, give me cars to vault and random people to accidentally smash into. better combat controls, too, something like Zeno Clash or Breakdown for the hand-to-hand would make it very interesting, also better moves that involve the environment in some way and the free-running skills. Also give us windows to smash through, obstacles to tip over if we're being chased, attack dogs to avoid, a GPS style map system that allows us to drop down waypoints that we set ourselves so we can follow the route we want to take.
TL;DR
Make it like a first-person version of Assassin's Creed without the swords and hidden blades and set in the world of the Mirror's Edge city.
If they'd done that, Mirror's Edge would've been a pretty good game.