
this is the N64 bio sensor. you plug the cart into your controller, and clip the other end onto your ear. this tracks your heartrate and sends the information to whatever game you're playing with it
whatever game you're playing with it, by the way, is a fully-english japanese exclusive called Tetris 64. there isn't another game the nintendo 64 bio sensor works with. it was designed for, and packaged with, Tetris 64
anyone have any tips for fucking around without finding out? i'd like to skip that part if possible. thank you!