The Real Reason Chemical Plant Zone Was So Crushingly Hard

Picture this: You’ve just beat Sonic the Hedgehog 2’s first boss. It was easy, you’re feeling confident after having a nice stroll through the lush surroundings of Emerald Hill Zone.

Now you’re in Chemical Plant Zone and you’ve got to worry about drowning, falling to your death in water, tightly-packed platforming with the threat of drowning again, and a boss fight when the ground shifts from under you. Surprise!

The difficulty spike in Sonic 2 is legendary. The first time Chemical Plant Zone loads, gone are the vibrant colours and warming aesthetic. Now you’re in hell. Everything sucks. This polluted misery dump is the polar opposite of what you expected.

It’s not uncommon for the Sonic games to go from one visual extreme to the next. Marble Zone in Sonic the Hedgehog doesn’t follow on from Green Hill Zone at all. But then while Marble Zone did introduce the player to some new mechanics, there weren’t split-second reactions or as many instadeath traps waiting to consume players’ patience, so what gives? Why was Chemical Plant Zone so hard?

As it turns out, Chemical Plant Zone wasn’t Sonic 2’s second zone. In fact, there’s a chance Chemical Plant Zone originally had a different name: Death Egg Zone.

The Working Theory

Image showing Mecha Sonic's spindash in action.

There’s a host of evidence that gives this claim some basis for those who look a little deeper.

First up, both Chemical Plant Zone and Death Egg Zone use the same assets. The most noticeable one is the yellow and black hazard design. You see this throughout Chemical Plant Zone. When doors snap shut, they use that design. In Death Egg, the same design in is used for the floor in the Egg Robot fight and a smaller version is used along the hatch Eggman sits inside of during the Mecha Sonic fight.

Also, here’s a fun fact. Eggman has an unused laughing animation during the Mecha Sonic fight. When Sonic loses rings, the animation plays to taunt the player. There’s logic in giving players rings at the start of the fight to tide them over. But as anyone who’s played Sonic 2 will tell you, Death Egg houses exactly zero rings, making the animation redundant. Did Sonic Team originally plan to include rings? Maybe.

Anyway, back to it. It’s not just the hazard signs. Entire pieces from Chemical Plant Zone appear in Death Egg Zone, albeit with a slight palette change.

Not seeing it yet? That’s fine. Think about some of the sections in Chemical Plant Zone, specifically where Sonic drops into water and dies. As mentioned, Sonic can exist in water and is unharmed until he runs out of air. But in Chemical Plant Zone, water can cause him to fall to his death. Interesting.

Now reimagine this scene. What if there’s no water. What if Sonic has just taken a trip on, say, a plane flown by Tails into outer space and instead of water, there’s just the empty vacuum of space beneath him? Sonic does die when he falls into empty holes, after all. Suddenly that section before the Chemical Plant boss seems a little more ominous.

The final part of the theory is all in the music. Death Egg Zone features three songs. Two of them are the boss fight music for Mecha and Egg Robot respectively, but then there’s a third when the stage first loads. It’s a killer track, and yes, like you, I also sat there listening to it fully before jumping into the Mecha Sonic fight.

The Death Egg Zone main track always felt out of place. It fits the zone effortlessly, but why make an entirely new track, and one of this caliber, just for the three seconds before Sonic drops into a fight and the music shifts? What if this music wasn’t just a placeholder for the start of the level and was actually intended to be Chemical Plant’s main theme when Chemical Plant was Death Egg Zone?

Sound plausible yet? Some believe so. So many, actually, that there’s even a romhack called Sonic 2 Long Version which features the diabolical Chemical Plant/Death Egg mashup in all its awful, awful glory.

Something a Little Meatier

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Theories are fun. Whether they’re right is irrelevant. So long as they’re interesting enough, that’s all that matters. Just ask anyone who browses Reddit.

There is a little more to this than circumstantial evidence, though. Remember the Sonic Jam Official Strategy Guide? Me neither, but there’s an interesting nugget of information on page 39 with regards to Chemical Plant Zone, as translated by a Sonic forum user and verified by me after a deceptive amount of time and work.

“At first [Chemical Plant Zone] was set to appear after Zone 10,” says an unnamed Sonic Team developer.

“Although there would be fewer Acts this time, we thought having about 18 zones would be good, but having each zone stand out and fit in the story, in a way that was easy to follow – in the end it dropped down to 11 zones, and Chemical Plant was placed as the second stage. In the end, it was a success (laughs).”

After zone 10? So Chemical Plant was originally intended to be a zone later in the game? You can see where I’m going with this, so I’ll leave you to decide whether this theory is a hill worth dying on (it absolutely is, though!).

Wesley Copeland
Wesley Copeland

Wesley Copeland is a gaming, tech, and toys journalist with over 10 years of experience writing online. Originally starting in video games before specializing in tech and toys, you can find his bylines at IGN, VG24/7, Kotaku, Tech Radar, Games Radar, PC Gamer, Heavy, and many more. He's also highly passionate about how tech can be used to better our day-to-day lives.