Xbox 360 and Xbox 1st Backward Compatibility Program allows players on Xbox One and Xbox Series X | S play hundreds of projects. However, not all games are backwards compatible – some of them did not pass the licensing rights, and others the Xbox team could not bring to the point where they could be played comfortably.
It’s now possible to play some of the Xbox 360 titles that aren’t in the backwards compatibility program by using the XENIA emulator. The XENIA emulator has been released and is available for free for the new Xbox consoles, and you can watch a video below on how to install it (no developer mode required).
More information about the emulator itself can be found on the official website of the emulator developers, and at this link you can find a list of games that support emulation, as well as information about the problems that projects face during emulation.