A group of researchers is currently investigating this barrier and found it to be a potential threat. The light and dark worlds once separate are colliding. The border between the two words is weakening, and if it were to break, the worlds would crash into each other and nothing would remain.
Therefore, the researchers have tasked Mario to find a way into the border and fix this impeding threat. But Mario can't do this alone. In order to ender the barrier, Mario must gather items from both words, and like every other inhabitant from the light world, he is unable to cross to the dark side. In order to save both words, Mario will need the help of his twin from the dark word.
Hi, so this is the project we're working on. I'll talk about the hack’s mechanics in a bit, but first, I want to clarify what "we" stands for:
Ckristina Level Design/ASM
Kixune OW Design/Graphics/ASM
yupilongas Level Design
As you probably guessed by now, this is a story-heavy hack. The main theme is duality, specifically the duality between light and darkness. The world map will be divided in two: Light and Dark with the Mirror Border separating the two. Each world is an inverted reflection of the other, for instance water in one world is lava in the other. The Mirror Border cannot be crossed, so in order to explore the dark world, you will need to take control of Dark Mario.
So, are Mario and Dark Mario's journeys completely separate? Well, no. Even if they cannot interact with each other, they can affect each other's worlds. Anything that happens in one side of the border, will have an impact on the other side.
In order to get to the bottom of every level, you will need to visit them from both sides to open new paths.
NOTE: Due to how the game handles 2 Player mode, it's impossible to save the game. The hack uses SA-1 so use savestates at your own risk. The hack is perfectly beatable in under 2 hours without saving (via savestates or otherwise).