The Chemical Plant is set around an active cityscape at night. In the background, detailed 3D-looking sky scrapers give off a healthy red glow into the night sky, with windows lit up and bright lights ablaze. Lower buildings are green, while down at the bottom of the background, you've got the presence of the grimy factory, with all manner of technology going on. There are thick black and grey funnels and railings, and even lower, a grungy, sickly green metal wall filled with moving air vents, pipes, tubes, meters and flashing doo-hickeys. Between the two contrasting settings appears to be an interesting white coloured section of water, which also reflects the green buildings at the top. The factory is possibly sitting on a polluted lake in the middle of the urban environment.

The nearby ground is in typical mechanical style, with a pale grey colour to it, but looking fairly dirty in some areas, and the separate rectangles of material are all bolted down. There are various pieces of machinery embedded within it, plus blue, red and yellow piping, see-through framework and patches of yellow and black "danger" stripes, to spice it all up a bit. The speedy slopes and curved roads work independently of the grey structuring, and are made up of long tubes containing blue chemicals, with a yellow road surface on top, whereas the straighter sections have no particular road surface as such. Adding more confusion to the already busy atmosphere, clear piping, which your character will spin through at speed when he reaches the entrances, covers certain parts of the level, and like Star Light Zone, there are also large grey girders and chunks of structural framework behind and in front of your view of the character. A very active place.

Large and in charge, this zone takes you all over the place, and you get the feeling every bit of space has been covered as Sonic and Tails leg it from one direction to another. This is probably the first, really huge type of Sonic level that's filled with a complicated array of routes that separate and converge across an intricate design, which is a bit of a headache for someone like me who's given himself the task of deciphering it! There's a good blend of extremely high-speed paths and also slower, more complex areas which rely on good timing and accurate platform hopping. The high-speed paths are probably the fastest in the 16-bit era, and contain weaving, intertwined pairs of roads that each lead to a separate route at the end, very steep diagonal slopes, and of course the ever necessary loop-de-loops (often two or three in a row, leading downwards) and curved ledges. If you go fast enough through these, you'll actually find that the screen may have a hard time trying to keep up with your character. The structure is fairly thin, containing groups of small blocks of ground floating around the map, with thin, sloping and twisting paths that provide all the speed, connecting one piece to another. There's usually a fair amount of open space around because of this, but there are also some small corridors of both horizontal and vertical nature, though not many.

There's a network of tubing all over the place which allows you to hop in from one spot, and come out in a whole other area of the act. These entrances usually have two different pipes going out of them, and which one you go through seems to be decided at random. That said, from what I've researched, Sonic usually goes through the same one for each occasion, and when playing Sonic 2 + Sonic & Knuckles, Knuckles invariably goes through the other, but Tails isn't quite so partial to either tube. Pretty strange. Sometimes both tubes lead to the same place, while other times they can take you to two completely alternate routes. Act 1 has three main routes, generally occupying the top, middle and bottom areas respectively. They're separated from each other near the very beginning (described in Point #1), but rejoin at various places near the end, also splintering into short sub-routes too. Act 2 meanwhile is laid out a little differently in that it mostly has one main route through it that branches, on three or four occasions, into two sub-routes that rejoin shortly afterwards, although one particular separation is quite long, taking up the most part of the left side of the map. Unlike Act 1, which mostly leads to the right, Act 2's main route weaves back and forth over large areas to take up most of the map, making for a fairly lengthy act.

Despite everything that's going on in the level, obstacles actually aren't as varied or numerous as you might expect. The moving platforms are designed kind of like Robotnik's egg-mobile, and feature regularly. You'll often find two of them side by side, moving up and down in opposing directions in a narrow, vertical passage, and also pairs of little ones that move around each other in a circle. Horizontal springs and the very first black spinning-disc zippers send Sonic or Tails speeding along the pathways in one direction as soon as you lay a foot on them, and the clear glass piping all over the place makes for a great, quick transportation method to get you from A to B. Just jump and break into a square grey entrance when you get to one, and you'll be sent spinning through them, to end up at an entirely different point in the level. At the end, the exit hatch closes, and these are fitted with springs on top. In corridors, groups of strange, harmful blue chemical bubbles will travel up and down from one tube entrance to another, which are positioned along the floor and ceiling. Watch their patterns and walk across at a safe opportunity. In open areas where both tube entrances are on the ground, the blue bubbles will actually jump across the air from one tube to another. Yellow and black doors will close in corridors where you are only permitted to travel through from one particular direction.

Like Star Light Zone again, there are bridges made of small yellow and blue square platforms that move up or down upon contact, creating steps for you. These can also be found separated, acting as single, small platforms that move slowly in a certain pattern, or in a group, where they will slide back and forth in diagonal formations. Don't take them too lightly, as they can crush you into the ground or walls in some sections. Some chunks of the thin yellow road disappear at regular intervals by moving to the bottom of the chemical tube they're placed on, where you can't land on them. These chunks are usually in a row of two to four, switching one after the other, and you'll fall through if you make your move at the wrong time, which could be fatal. The road can also sometimes be broken up, leaving small yellow platforms that move back and forth across the gap, offering you a lift from one side to the other. These are positioned over the pools of chemicals, so be very careful when boarding and leaving them, as it often means death if you fall in where there may not be anything underneath to support you.