Labyrinth Zone boss (8-bit)

The Labyrinth Zone boss is a vehicle that appears in the Sega Master System and Sega Game Gear version of Sonic the Hedgehog. It was a submarine-based Egg Mobile created by Dr. Robotnik that the doctor used to battle Sonic the Hedgehog.

Appearance
The Labyrinth Zone boss is a submarine-based Egg Mobile that's identical in appearance to the Bridge Zone boss. Just like it, it's oval in shape and consists of a gray and black main capsule with a transparent window on its top. It also its two turrets on each side of its top and ventilation holes in the shape of stripes on the front. It also possesses the Bridge Zone boss three gray turbines for movement; two on its sides and one on its underside. Color-wise, it is also like it, mostly dark gray, with a yellow circle on its front and a black underside. It also has the trademarked yellow and black hazard stripes on its sides.

Powers and abilities
Robotnik's submarine can, like all submarines, dive and move underwater. It can also attack by shooting energy balls from its turrets. It can also now, unlike when it appeared in Bridge Zone, shoot homing rockets towards Sonic.

Sonic the Hedgehog (8-bit)
In the 8-bit version of Sonic the Hedgehog, Dr. Robotnik used this vehicle to attack Sonic when he arrived at the end of Labyrinth Zone. In spite of Robotnik's efforts though, his vehicle got destroyed by Sonic in the end.

Battle
The Labyrinth Zone boss is the fourth boss of Sonic the Hedgehog. The player fights it at the end of Labyrinth Zone Act 3.

Boss guide
In Labyrinth Zone Act 3, after climbing some underwater blocks, the player will arrive in an empty area with a bottomless pit in the center and two holes in the right and left sides of the ceiling. Robotnik will then arrive from the center pit of the boss arena in his vehicle, initiating the boss battle.

First, Robotnik will attack using its turrets before diving into the bottomless pit. He'll then reappear from the left hole in the ceiling and descend into a height low enough for the player to hit him, attack using a missile, and come back from where he came from. He'll reappear again, this time in the right hole of the ceiling and re-do the same thing as he did in the left ceiling hole. From there on, Robotnik will repeat this cycle from the bottomless pit again and again until he's defeated.

During the boss battle, Robotnik will attack using either his turrets or his rockets depending on wich hole he stands in. If he's in the bottomless pit, he'll attack by shooting two energy balls from the top of its turrets towards each corner of the boss arena. To avoid the energy balls, the easiest way is by jumping at the right time toward the center of the boss arena and come back towards where you jumped. If he's on one of the ceiling holes, a rocket will appear on its underside before homing towards Sonic direction. Despite being able to track Sonic, it's also easy to dodge them by jumping but be careful not to hit them in the process.

Once Robotnik has taken eight hits, he'll be defeated and flee in his exploding Egg Mobile, allowing the player to open the metal cage and complete the Zone in doing so.