Robo-Sandy has no difference in body shape from the real Sandy. The flower on her helmet is replaced by a bouncy antenna. The patch design on the suit is a bolt instead of an acorn. There are no colored stripes on her arms. Her eyes are green lenses and her mouth has a speaker. Under the head is a button that reads "BOOM!" She takes damage if it is struck in Phase 3.
The battle takes place inside the Poseidome, a large stadium with a full audience that includes a large scoreboard hanging over the arena. During the second phase after Robo-Sandy's head hits the scoreboard too many times, it collapses and falls to its side, laying on one side of the arena up to the last stage.
Robo-Sandy will walk a few steps, before performing her basic attacks, such as an elbow slam, and a body slam in the center. She will become temporarily stunned, and lift the player into the air, encouraging them to use Bubble Bounce. Robo-Sandy's head will then depart from her body, and hit the scoreboard, getting electrocuted. After two more hits, the scoreboard collapses, transitioning into the second phase.
Once the scoreboard collapses, Patrick insists SpongeBob into switching turns with him during the second round, in which he agrees to do so out of vexation. During this phase, Robo-Sandy will become mildly more aggressive by performing the 'Old Clothesline Move' with her attacks. When she slams herself in the arena, the player can use Patrick's Body Slam move, removing her head before she can get up. The player must pick up the head with his great strength and toss it into the exposed wires of the damaged scoreboard, causing the robot to become further electrocuted. Robo-Sandy's body will stretch out her arms in search of her head. If the player does nothing while she is decapitated, her head will fly back to her body.
Patrick switches with SpongeBob during the third round, much to his dismay. Robo-Sandy will perform moves in a much more excessive rate and will use all her limbs to perform the 'Old Clothesline Move' on the player. When the player plops Robo-Sandy's head, it will still remain in her grasps but will expose the button underneath as she temporarily sways it. The player must use Bubble Bash to hit the button, which will toss her head back to her body. After repeating this two more times, Robo-Sandy is subdued and falls to her defeat.
In the GBA Version, Robo-Sandy tries to stomp on SpongeBob somewhere not too far from Sandy's treedome. The objective is to avoid contact Robo-Sandy during her leaps and to stomp on the robot's head to crack the helmet. When the robot's health bar has been depleted by half, Robo-Sandy will utilize more attacks, such as using her hands to attack SpongeBob and creating an electric field over her helmet to protect it from damage.
Karate chop: Robo-Sandy will slam her elbow into the ground, creating a short shockwave of dust on the arena. SpongeBob or Patrick will get hurt if they come into contact with the wave.
"Old Clothesline Move": During the second phase, Robo-Sandy will slingshot herself across the arena, revealing springs that attach to her limbs that are flung towards SpongeBob or Patrick. She will only use her legs during the second phase, and then her arms as well during the third.
Body slam: Robo-Sandy will make a great leap and slam herself into the ground. She will be stunned temporarily, allowing SpongeBob or Patrick to use Bubble Bounce or Body Slam respectively, to plop her head-off.
Swipe: When SpongeBob or Patrick get too close, Robo-Sandy will perform a low karate chop towards them, causing damage.
Hopping: Robo-Sandy will hop across three levels of ground during the battle. If Robo-Sandy lands on SpongeBob the latter will be damaged.
Long chop: When her life bar has been depleted by half, Robo-Sandy may extend her left hand to hit SpongeBob, causing damage.
Static Helmet: Robo-Sandy's helmet will form an electric field to protect it from SpongeBob's attacks.
Unlike Robo-Patrick or SpongeBot SteelPants, Robo-Sandy seems to be mute, as she does not produce any verbal sounds during the battle, whereas Robo-Patrick screamed in his defeat, while SpongeBot attacks by screaming "kah-rah-tae."
Robo-Sandy is the only boss to actively strike when she gets too close to her opponent.