The boss battle takes place on a yellow platform over a lake of toxic purple liquid (Mega Mack). On either side of the arena, there are three platforms that flip over and drop anyone standing on them into the Mega Mack, which spells instant death.
The boss itself is Dr. Robotnik in his Eggmobile, which has been modified with a canister over Robotnik's head and a system of tubes that can fill the canister with Mega Mack from the lake beneath (although the liquid in the canister appears blue rather than purple). When the canister is full, Robotnik will attempt to dump the contents on top of the player.
- This boss can actually be defeated very easily by running right up to him at the start of the battle and bouncing off him repeatedly while against the right edge of the screen. No controller input is even required at this point.
- In a prototype version of Sonic the Hedgehog 2, sprites of Robotnik have been found where he took the chemicals and accidentally dumps them on himself. This might have been an ending sequence for this zone, but was removed.
- If the player is crouching, the dropped Mega Mack won't deal any damage.