Information about the Zone
First appearance : Sonic the Hedgehog 3 & Knuckles (1994)
Game appearances : Sonic the Hedgehog 3 & Knuckles (1994), Sonic Mania (2017).
Zone description : Located on Angel Island, a sunken underwater city, Hydrocity Zone, like everything on Angel Island, is full of secrets, dangers and relics of ancient civilizations. This sunken city is probably the remnants of the ancient echidna nation of Knuckles Clan, destroyed by Chaos long before the events of the games. The still-working mechanisms of the ruins, which pose a real danger to those who were not lucky enough to get here, show the advanced building technology of the ancients and their desire to protect their secrets.
OSTs used in this Zone
Sonic the Hedgehog 3 & Knuckles (1994) [Act 1]
Sonic the Hedgehog 3 & Knuckles (1994) [Act 2]
Sonic Mania (2017) [Act 1]
Sonic Mania (2017) [Act 2]
Sonic the Hedgehog 3 (1994)
After his defeat, Dr. Robotnik lands on Angel Island, where he finds an energy source even more powerful than the Chaos Emeralds, namely the Master Emerald. However, it was protected by the powerful guardian Knuckles the Echidna. Despite his power, Knuckles is rather gullible, so Robotnik convinces the echidna that Sonic and Tails are trying to steal the Master Emerald, thus turning Knuckles against the heroes. Soon, Sonic and Tails arrive on Angel Island and are immediately attacked by Knuckles, who takes the Chaos Emeralds from the heroes and hides them in Special Stages portals around the island. Sonic and Tails have to search all over Angel Island to find the portals in the form of giant rings while chasing Robotnik and Knuckles along the way.
After heroes defeated Dr. Robotnik in the Angel Island Zone, Knuckles suddenly appears and destroys the wooden bridge under Sonic and Tails, causing the heroes to fall into the Hydrocity Zone. As they make their way through the flooded ruins, Sonic and Tails encounter Big Shaker, as well as Dr. Robotnik himself in his new modification of the Egg Mobile, the Egg Vortex.
After destroying the Launch Base Zone, Sonic and Tails followed Knuckles into one of the portals, but it did not lead to the Special Stage. Instead, it led them to the Master Emerald altar. After placing the Chaos Emeralds around the Master Emerald, Sonic and Tails find the portals to the Special Stages again, where they energize the Emeralds, turning them into Super Emeralds with the power of the Master Emerald. Using the power of the Super Emeralds, Sonic and Tails finally defeat Knuckles and Robotnik.
Sonic & Knuckles (1994)
After the defeat of Dr. Robotnik, however, many of the evil doctor’s robots and machines remained on the island. One robot, called Egg Robo, had enough intelligence to replace Dr. Robotnik and rebuild an army of robots and weapons itself. After dropping bombs on Knuckles, Egg Robo steals the Master Emerald, forcing echidna to go in pursuit. Like Sonic and Tails, Knuckles also visits the Hydrocity Zone where he also battles Big Shaker and Egg Robo in the Egg Votrex machine.
On the way, Knuckles finds seven Chaos Emeralds and applies them, activating the form of Super Knuckles. After destroying Launch Base, Knuckles enhances the Chaos Emeralds on the Master Emerald altar, turning them into Super Emeralds. Using their power, Knuckles transforms into his Hyper Knuckles form. Eventually, Knuckles catches up with Egg Robo at Sky Sanctuary, defeats Neo Metal Sonic and retrieves the Master Emerald. After his victory, Knuckles returns Master Emerald to its altar and restores peace to Angel Island.