I got Gravity Rush for my PS Vita about 6 months ago and I still haven't played much past the first chapter. I find it very hard to find space in my life for playing mobile games. When I want to play games, I do so for relaxation and I'm already at home in my couch preferring the big ass TV. There is no other space in my life where I could cramp in playing.
About this game, it is fun but not extraordinary. There is one element that is pretty unique, where you shift the gravitation and "fall" in any direction. It sounds weird but work very well.
The story or the characters are not very interesting and that is probably why I'm not bound to this game. I hope I will complete it someday when I'm stuck at an airport.