Egg Scorcher

The boss found in Marble Zone is an easy boss. Robotnik fights by shooting fire on the platforms from above. He'll do one platform at a time, and will move back and forth while doing so. Begin this battle by standing on the left platform. When he approaches you, quickly hit him once, and then jump over the lava and onto the other platform to avoid his fire attack. When Robotnik gets near you again, hit him once, and then jump to the other side. By this time, the fire should've cleared itself on the other platform. The process repeats from here. Overall, an easy boss. It takes eight hits to put him to rest...for now.

Once again, after the battle, head right and step on the switch to free the animals.