Twin stick shooters have been around forever, so coming up with new ways to iterate on the genre can be a challenge. Often they wrap around some sort of leaderboard where you fight through endless waves of enemies and try to score better than your buddies. Others have a sort of story or progression (Smash TV springs to mind) that you are trying to work through. No matter the theme wrapped around it, the basic game is still the same: move with one stick, shoot with the other and stave off hoards of enemies that are trying to kill you. After that, it becomes largely about execution, and on that front Geometry Wars 3: Dimensions does an excellent job.
