Mystic Cave Zone

"Robotnik's been digging for Chaos Emeralds in this eerie forest of flickering lights, glow-worms and stinging centipedes. Hang onto the ivy to discover escape routes."

- Sonic the Hedgehog 2 manual description

Mystic Cave Zone is the sixth Zone in Sonic the Hedgehog 2. As with most other Zones in this game, Mystic Cave Zone consists of two standard Acts with a boss fight at the end of Act 2.

Description
After braving the subsurface magma chambers of Hill Top Zone's volcanoes, Sonic now descends deeper underground to the dark, yawning caverns beneath West Side Island's mountain range. Mystic Cave features moss-covered rocks and dangling plant tendrils within these dimly-lit subterranean spaces. Impassable walls can be lowered to form convenient bridges if you are sharp-eyed enough to spot the hidden switches within the slimy vines that hang from the ceiling.

Dr. Robotnik has deployed a variety of fiendish Badniks within the caves to slow our heroes down. Crawlton snake-bots are particularly frightening; like a scaled down version of Gigalopolis Zone's Bead Worm Boss, the blue-yellow segmented worms spring out at you from hidden nooks, with their heads being the only weak point. Flasher firefly-bots hover around enveloped in forcefields of light and the only way to destroy them is to wait until the shield peters out.

The second act is notorious for having a particular part in which the player must grab a vine or else drop into an inescapable pit of spikes, which would be especially troublesome for Super Sonic. However, in the 2013 mobile re-release of the game, the spikes were removed to reveal a special secret passage underneath a wide drop: Hidden Palace Zone.

Boss


In this Zone's boss fight, Dr. Robotnik attacks with a double-barreled drilling machine. He's been mining in the caves in search of the Chaos Emeralds. This burrowing mech tunnels into the roof of the cavern, dislodging rocks and stalactites which rain down injuriously on Sonic and Tails. After bombarding the heroes with debris, Dr. Robotnik's mecha descends and comes at them with its drilling arms. Dodge and jump on Dr. Robotnik to defeat him.

Sonic Drift 2
Mystic Cave also appears as a racecourse in Sonic Drift 2 for the Sega Game Gear. This stage is the fifth track of the White Grand Prix (White being the intermediate of the three available tournaments), coming after Hill Top and before Emerald Hill. Unlike the majority of races in the 2nd Chaos Grand Prix, this isn't a three-lap circular course; the objective is simply to get through the tunnel system ahead of everyone else.

Sonic the Comic
In Sonic the Comic, the Mystic Cave Zone is the base of Captain Plunder's Sky Pirates. The Zone is filled with Flasher and Crawlton Badniks, as well as spike traps, just like its appearance in Sonic the Hedgehog 2. It is accessible by Star Post (which in STC continuity allow instantaneous travel between Zones).

Sonic visited the Zone on two occasions. On the first time, he and the Freedom Fighters traveled to the Zone to rescue Amy Rose, who had been kidnapped by Plunder's pirates. The two groups nearly came to blows before Amy explained that it would be more profitable for both groups to work together.

Later, Sonic visited the Zone to investigate a cult called that Followers of Doctor Sun. Sonic discovered that Doctor Sun was really Robotnik in disguise, and he had been using the cult to turn children into Badniks.

Adventures of Sonic the Hedgehog
A cave that may have been intended to be the Mystic Cave appeared in episode "Slowwww Going" of Adventures of Sonic the Hedgehog. Scratch and Grounder took Sonic to the cave after hitting him with the Subatomic Slow Go Beam Weapon.

Sonic Underground
An unnamed cave appears in the episode "Harmony or Something" of Sonic Underground, as the home of the Oracle of Delphius. It was found by Sleet and Dingo, so Doctor Robotnik sent an attack squadron to eliminate the Oracle. The Sonic Underground got to the cave to warn him, but Sonic's rushing in without a plan stranded them on a rock. He and Sonia started arguing, but were interrupted by a vision of their mother, Queen Aleena. She implored them to work together, use their medallions and save the Oracle. Sonic and Sonia made up, and the three of them played "We're All In This Together". After the song, they defeated Sleet, Dingo and the SWATbots. As a reward for working together, the Oracle gave them the ability to use their powers whenever they wish.

Others
The Mystic Cave Zone also appears in Sonic v. Zonik, Sonic the Hedgehog Adventure Gamebook 1, Sonic the Hedgehog Adventure Gamebook 2 and Sonic the Hedgehog (Play-a-Sound).

Trivia

 * In a prototype version of Sonic the Hedgehog 2, Mystic Cave Zone is labeled Dust Hill Zone in the level select. This was probably a mistake, since Dust Hill Zone is one of the scrapped levels from Sonic the Hedgehog 2 and Mystic Cave probably didn't have an actual name at that point.
 * The 2 Player music of this zone was originally used for Hidden Palace Zone. It is unclear if this was a placeholder theme as there is a unique track assigned to it in the final version, but it ended up also being used for the restored zone in the 2013 mobile re-release of Sonic the Hedgehog 2.
 * This is the first zone to feature a boss that forces spiked debris from the ceiling.
 * The spike pit in act 2 of Mystic Cave Zone gets removed and becomes the entrance leading to Hidden Palace Zone in the 2013 re-release of Sonic the Hedgehog 2.