The Labyrinth Zone is the fourth boss of the 8-bit versions of Sonic the Hedgehog, fought at the end of Labyrinth Zone.
Labyrinth Zone's fight with Dr. Eggman sees the return of his submarine from Bridge Zone. Sonic begins underwater in the third Act, however he has an unlimited supply of air. When the player reaches Eggman, they will notice two banks on either side of the screen. there are three spaces in which Eggman can emerge: one on the bottom, and two on the top at left and right sides of the screen. Eggman appears from one of the gaps, and the player should jump on or under his pod to deal damage, but they must watch out; if Eggman emerges from the bottom space, he will shoot energy projectiles in both directions, but if he appears from either of the top spaces, he will send a vaguely-homing torpedo towards Sonic. These attacks are easily dodged, though good timing is necessary due to reduced mobility underwater.
After eight hits, his craft explodes, and Sonic can escape the watery depths to Scrap Brain Zone.