If you're looking for an RPG you should check elsewhere because at best this game can be considered a Diet version of an RPG. Maximum fun – minimum story. For an RPG/FPS mixture you need look no further than Fallout 3 or Bioshock as both titles have much more going for them than you'll find here. Having said that, if you're looking for a fun game with lots of guns and explosions this is definitely the title for you.
If the creators had only included something worthy of the RPG label, for example an interesting story with well-rounded characters, this could easily have been an excellent game. Borderlands is the type of game which gets better the longer you play.