Chemical Plant Zone is the second level of Sonic the Hedgehog 2 for the Sega Mega Drive, coming after Emerald Hill and before Aquatic Ruin Zone. As with most other stages in this game, Chemical Plant consists of two standard Acts with a boss fight at the end of Act 2.
General
Chemical Plant Zone takes place in an industrial cityscape, filled with toxic gloop, mechanical creatures, and twisting chemical pipes. Some players consider this level disproportionately difficult, given that it's only the second stage; it has many difficult obstacles, often requiring fast reflexes (or, failing that, luck).
Suction tubes wind across the level; a miscellaneous terrain feature that sucks you in and deposits you at the other side of the tunnel. These cause no damage nor have any effects other than transportation. Yellow-clad pipes filled with blue chemicals spiral through almost the whole map. They can have very steep drops and may climb after a drop. These can sometimes end badly, such as if one throws you onto a cliff into the water. To avoid dangers on these, stay alert while moving.
Blocky collections of yellow/purple squares move back and forth periodically. You must jump onto them and then jump onto either the other square next to it or solid ground. These require a knowledge of the game physics and quick reflexes. For people who do not have these, the moving squares can be the hardest part of the level.
The rising pink chemical waters (a substance un-named in the game but known as Mega Mack in Sonic the Comic) during act two sees the water level rises and the only way to escape to land is by climbing up shifting blocks, as explained above. This is a very dangerous segment, as you are not only at risk of drowning, but also at risk of being crushed by the spinning paths.
There's also the ever-delightful blue chemical jets; these require very quick reflexes, as they are incredibly deadly. They are a jet of sludge that shoots from one end to the other and back, or in a loop form. These cannot be killed, so just run past them and hope that you survive.
Badniks
- Mechanical Spider: These are suicidal spiders that will lower themselves to your height and attempt to grab you. The trick is to jump before they grab you, killing them. Tails can be very useful with these, as when he dies you do not lose a life. These spiders explode after a successful attack, so you can use Tails to your advantage with that.
- Spiny: These are very deadly. They have a mechanical "mouth" that opens to fire bolts at you. They can be found on any surface, including the walls. They have a knack for being at the end of high speed areas, making them extremely dangerous. You will also find them hard to kill, as they can sometimes seem invincible.
Boss
Knuckles vs. the boss
The boss is Doctor Robotnik in a floating vehicle that can create sludge "bombs." He will hover over the pink water as his overhead canister fills, then and will drop them on you once done. If that weren't hazardous enough, you fight on a solid platform surrounded by considerably less solid edge segments. Many people have killed the boss only to die by falling off the bottom of the level on the dropping squares. As usual, Tails helps a lot here, as he can help smash Eggman's machine sufficiently quickly that you don't fall prey to a misstep.
Sonic the Comic
The Chemical Plant Zone also made several appearances in the UK publication Sonic the Comic.
In its first appearance, the Chemical Plant was a forced labour camp for the Emerald Hill Folk. Lazy workers were struck by Trooper badniks with electric whips, or made into organic batteries for badniks. Sonic infiltrates the Zone disguised as the penguin Bob Beaky and managed to free the captives, although they were ambushed on the way out by Megatox, a villain made entirely of the pink substance called Mega Mack.Cite error: Closing </ref> missing for <ref> tag