Robotnik's machine has three phases in three different arenas. Each phase requires three hits before defeat.
In the first phase, he'll use mace weapons at the ends of the arms, and an alarm will go off if one detects Sonic's presence. The solution to defeating the first phase is to attack the shoulder alarms once the maces thrust forward.
The second phase contains hedgehog-seeking flamethrower arms, the same used in the Volcano Valley Zone boss. However, instead of luring the flames into the scientist, the key is to attack the shoulder area in a certain position.
The final phase involves a series of ice projectiles, which ricochet around the walls. The best chance of not getting hit is to stay in the corners behind the ice-shooting arms, as the projectiles don't bounce into that direction.