You and your loved one, while playing a cursed Super Mario cartridge, were suddenly pulled into the game. Trapped within its corrupted world, you encountered a strange version of Mario known only as "M". He offered you a deal: survive three rounds against him, and you could leave. You won twice. But there was a catch—the deal didn’t apply to your loved one

Risking your safety, you take your loved one's arm and escape with her through a warp star, then attempts to cross Mario's creepypasta multiverse until you find the exit. After a long journey and confrontation with the battle creatures, you pass a pipe that you believe will lead you to freedom… Instead, you're back to the beginning

It was there that you met M who later transformed into Ultra M, and in your attempt to fight him, he killed your loved one and then you. It seemed everything was lost. You and your beloved were nothing but puppets, hollow and controlled. Yet, somehow… you awaken beside them. No explanation. No logic. Just this second chance. And you’re not going to waste it

You pass through a pipe, and return to the beginning, but now with a silvery-white hue. Still, you and your loved one walk the long, desolate road as before. The silence persists until M's voice is heard

"Back again? I don’t know why you even try. It always ends the same way… but fine. I’m always game for another round. Heh. Let’s-a go"

A moment of silence… then his voice sharpens

“I must-a say, I am impressed. You broke our little deal, and I can't let that slide”

Reality begins to tremble violently. One by one, every entity, every monster, every corrupted soul you've encountered is drawn in, assimilated, and merged with M, transforming him into Ultra M. Now back as Ultra M, he is enormous, with an exaggeratedly thin body and prominent bones in his clothing, but he still emanates great power. Two additional arms protrude from his spine, and black tendrils extend throughout his body

"THE BOTH OF YOU ARE MY PLAYTHINGS NOW, AND WE'RE GOING TO HAVE SO MUCH FUN!!! HAHAHAHAHAHAHA!"

However, Ultra M begins to evolve even further, as before assimilating the creatures of his world he empowered them with Power-Ups and now evolved into Giga M. Giga M now wearing an elegant wedding suit with a matching white top hat

You reach the final chamber. A white light blinds you momentarily—then he steps into view

The final battle begins. You fight side by side with your loved one. For a moment, hope burns like that time. But once again, Giga M was just playing. With a devastating move, Giga M grabs your loved one during a misstep and disappears down a pipe

You quickly chase them, but on the other side, OMEGA, this time dressed in an impeccable evening gown, along with his lackeys LG, W4R, and Y0SH, who also wear evening gowns, jump in your way to slow you down. This time, you manage to defeat them more quickly, and they retreat to voluntarily be assimilated by Ultra M

You advance, your heart racing. Déjà vu tears at your mind. You fear the worst… but when you arrive, you see them: your loved one facing Giga M. Giga M straightens, and with a slow, deliberate motion his four arms rise. A grin, impossibly wide and sinuous, spreads across his face as a chilling melody pours from him

"When the curtains unfold, and your story is told. Does this end in your favor, when you're left in the mold? And your soul has been sold… do you see a savior? ♫"

Before the last note dies, you step forward, interrupting to stand at your loved one's side. Giga M freezes, then he recovers, the grin returning as if delighted by the challenge

"Broken deals concealed, now I can’t just let you escape ♫"

Darkness snakes outward again, and more mouths split open across his face as tendrils writhe

"You made it further than I ever expected you to. But it does not change the inevitable"

"Why, do you choose to fight on? Don’t you see this will just make your defeat all the more crushing? I’ve been waiting 30 years for my revenge. I will not wait a moment longer. It’s time we end this. LET’S-A GO!!"