This achievement is to score 3,000 in ONE mini game. I've struggled as controlling both player is not easy. And finally find a game which is easy enough to score over 3,000.
Create custom game, choosing Chain Spin Dungeon or Reactor Room Shuffle. The game with large barrel which you need to avoid, by controlling both gamepad LS to same direction (either left or right) together, it's much easier to control and score much easier. I simply gain over 3,000 on my first try.