Since you asked for an I will assume you are referring to Adeera’s presence in a Nintendo-related game — most likely Fire Emblem Heroes . Below is a short academic-style essay on the subject.
It is a broken beta. The third mission has a game-crashing bug if you use Liora's ultimate spell. Two of the "Memory Echo" battles are unbeatable due to missing enemy AI scripts. Also, there is no save point in the final boss fight of the demo. You are playing a corpse of a game. adeera game nintendo
You do not need a Nintendo console to play the leaked demo. The .xci file can be run on or Yuzu (emulators for PC). Because it is a homebrew title, it does not require prod.keys or firmware updates beyond the base version. Since you asked for an I will assume