Gigalopolis Zone

Gigalopolis Zone is the second level of Sonic Chaos for the Sega Game Gear / Sega Master System. In keeping with the other stages of this game, Turquoise Hill consists of two standard Acts followed by a shorter, third Act which contains the Zone's boss.

Gigalopolis Zone (called Gigapolis Zone on the Game Gear, most likely because the full name wouldn't fit on a smaller screen) sees Sonic run through an urban environment at night, under the stars. Some of the level resembles a construction site, with orange, metal frameworks and seemingly incomplete block walls. The background displays various high-rise buildings as well. Taken together, these features are highly reminiscant of Star Light Zone from Sonic the Hedgehog (16-bit); and since both these games take place on South Island, it would not be unreasonable to speculate that the two zones are close neighbours.

Boss
Throughout Sonic Chaos, and in a marked change of his tactics from other early games, our old friend Doctor Robotnik apparently thinks he's too important to face Sonic or Tails personally (until the last boss). Instead the Doctor deploys larger, tougher, nastier badniks as boss robots.

Gigalopolis Zone's boss is some sort of giant, upright, mechanical caterpillar. The machine attacks by lobbing the spherical segments of its own body in Sonic or Tails's direction. Dodge the metal balls and hit the automaton on it's glass-shielded cranium to defeat it.