Tetris 64 is a puzzle video game for the Nintendo 64. It was released only in English in Japan in 1998, and is the only Nintendo 64 game that works with the bio sensor accessory, which it included.
The bio sensor is a Nintendo 64 accessory produced by SETA and only available in Japan. It was sold on its own or packaged with Tetris 64. It looks like a Nintendo 64 controller pak with a wire coming out of it with a clip on the end. One end of the sensor plugs into the extension port on the Nintendo 64 controller, and the other end clips onto the player's ear. The device measures the user's heart rate and adjusts the game's difficulty accordingly.
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