The real essential features of an authentic Super Nintendo retroclone:
Title screen whose art style looks nothing like the rest of the game
Menu goes "bwoop"
Only ever hearing the first seventeen seconds of the best song on the soundtrack because it inexplicably plays exclusively in one particular transitional area where nothing ever happens
That one specific electric guitar sample
Doing stupid tricks with multi-plane parallax; bonus points if it involves a sunset
Default controller mapping assigns something odd to the shoulder buttons because the developers were still figuring out what to do with them
The player character walks behind a semi-transparent object
Important mechanics and/or critical plot information documented only in the game's attract mode, which it has in spite of not being an arcade port