Here is the full list of all 12 Sharpshooter Plus achievements.
Cleared all 20 unique minigames over time.
Achieved the AAA grade on any mode/difficulty.
Achieved an A or better grade on any mode/difficulty.
Scored 0 on a minigame due to penalties.
Shot all targets during the Final Round on any mode/difficulty.
Missed the target with your only bullet.
Completed full games of Sharpshooter using at least two different control methods (gamepad, mouse, touchscreen).
Achieved 100% accuracy during 3 consecutive rounds within the same game of Sharpshooter. (any mode/difficulty)
Cleared 8 consecutive rounds within the same game of Sharpshooter (any mode/difficulty).
Completed a full game of Sharpshooter having Cleared every round (any mode/difficulty).
Completed a full game of Sharpshooter with Insane Mode turned on.
Achieved the AAA grade on Expert or Master difficulty.