Knuckles appears as he would appear in Sonic Boom. But his regular shoes are replaced with cleets.
Knuckles retains his personality from Sonic Boom.
In Story Mode
When Sonic and Tails enter Casino Night, he is seen facing Fang the Sniper, but is defeated by the weasel and falls down a cliff. After Sonic defeats Fang, Tails saves Knuckles. He joins the gang to defeat Eggman again. He faces Rogue the Bat in Angel Island and beats her to recover the Master Emerald. He also assists Tails on defeating Bark the Polar Bear when he is brainwashed by Eggman. Knuckles fought Mecha Sonic during the final battle with Eggman along with Blaze, Silver and Manic. He is then quickly knocked unconcious from Dr. Eggman along with Tails and the rest of heros, except for Sonic. Sonic turns into his Super Transformation to fight Eggman's Death Egg robot (if he gets all the Chaos Emeralds). Sonic destroys the robot and Eggman is blow away from the explosion along with Sonic and the heros.
Attack 1 - Knuckles jabs the opponent.
Attack 2 - Knuckles punches the opponent.
Attack 3 - Knuckles spin attacks the opponent.
Backwards Attack - Knuckles elbows his opponent's chest.
Side Attack - Knuckles roundhouse kicks the opponent.
Up Attack - Knuckles knocks the opponent into the air.
Down Attack - Knuckles punches the ground, damaging the opponent if they didn't jump in time.
Grab 1 - Knuckles grabs overhead and slams them down on the knee on the spine.
Grab 2 - Knuckles grabs the opponent head and slams it to the ground.
- Bare Knuckle - With the Energy Ring, Knuckles uppercuts the opponent and ragdoll throws them to the ground.
- Bone Breaker - With the Chaos Emerald, Knuckles smashes the opponent's head to the ground, shattering the skull. Then he snaps the opponent's leg.
Finisher Move: Super Spin - Knuckles starts spinning around and chases the opponent. The opponent starts running around until Knuckles catches them, punching them to the camera, cracking the screen.
- Knuckles breaks the fourth wall four times.
- Knuckles wonders how can the player can see him well when he wins a match under 20 seconds.
- Knuckles looks at the camera when Tails accidently lets go of him when trying to save him in Casino Night.
- Knuckles shouts boo to the player when he wins a match ending with a Time Over.
- Knuckles punches the opponent to the camera during his finisher move.