Spin Hammer Attack
From Sonic Retro
The Spin Hammer Attack (回転ハンマー), also known as the Revolving Hammer Attack, is one of Amy Rose's techniques, useable only in Sonic Adventure and Sonic Shuffle. The attack sees Amy twirl her hammer in a circle around her, spinning on the spot to knock out any enemies who enter her strike radius. Her Piko Piko Hammer trails pink hearts and an afterimage as she spins.
Activated by holding or and spinning the control thumbstick around in a circle, this attack is not available to Amy at the start of the game, requiring the Warrior Feather upgrade to use. Amy spins on the spot for a while, but eventually gets dizzy and staggers around drunkenly for a few seconds. The technique is not a particularly useful one mainly because Amy remains rooted to the spot for the duration (contrast Tails' Rapid Tails Attack with the Rhythm Badge), although the Long Hammer upgrade enlarges the circle of effect and thus becomes somewhat more practical.
In Sonic Shuffle, the attack is used as Amy's special battle ability under the name of the Revolving Hammer Attack. If she draws an S Card in battle, she will perform the move on the enemy, which always does 5 damage points.