This is a weird one, but I’d love to see a reimplementation of the sensor bar. The gyro controls haven’t cut it for me. I like how the Wii U game pad had the sensor bar built in to the bezel. The real engineering nightmare would be squeezing IR cameras into the top of the Joycon
Ehhhh…I have a few things…better games, more power, backwards compatible (because other people would like that, I don’t really replay old games).