Very good shooter with the very best movement mechanics! (I only played the campaign.)
You know the movement is good when you want to hop out of a huge cool powerful mech just to be a silly little guy sliding around on walls.
My favorite level was 'Effect and Cause,' and I wish the interesting mechanic in it was taken further.
I didn't really care much for the story or characters, but what this game really excels at is giving you unique environments to fight in and huge set pieces that make you feel cool while you wallslide and shoot at things.