If you own the game physically? You can't, because it was digital. If you bought it on the eShop in 2015, you have a moral (if not legal) right to back up your own copy using a hacked 3DS. If you never paid for it, consider the ROM a "demo" of abandonware, and buy the modern PC version to support the creator.

is a fascinating chapter in indie gaming history, marked by technical hurdles, corporate shifts, and the eventual creation of a unique, if flawed, handheld experience. While often overshadowed by more powerful versions, the 3DS port remains a significant milestone for fans of Edmund McMillen’s roguelike masterpiece. A Challenging Road to Release

You are copying copyrighted software without a license.

But the 3DS wasn’t empty.

He pressed the power button.

The ROM you will find is version 1.0 or 1.05. Afterbirth, Afterbirth+, or Repentance. There are no Greedier mode, no Bumbo, no Apollyon, no alternate floors. You are playing the vanilla Rebirth experience from 2014.

Want me to expand it into a creepypasta-style full story, or write another one with a different ending?