You're missing the point. Retrogaming is about creating the familiar feeling of
playing the games. A WiiU controller is not the same as a NES controller. HDMI is not the same as CRT + Scanlines.
Retro gamers generally play on the original hardware with CRT screens. If they can't do that, they play on emulators with using controller input converters and shaders or scanline generators. Gaming on a WiiU does not recreate that experience.
Watch the videos on this channel for more info:
https://www.youtube.com/user/mylifeingaming
