You take an Xbox game designed to run on an Xbox 360, a 64 bit PowerPC system and decompile its binaries back into source code. You now have the ability to modify the game as well as port it to other systems and architectures such as Windows on X86_64 or Linux on ARM64.

You take a binary that's intended to run on the Xbox 360, and emit a new binary that runs on a modern x86 computer.