Simplify the following text for a Grade 8 native English-speaking person.
Original: The introduction music for Mario Kart 64 , which is loosely based on the original Super Mario Kart theme tune , was remixed and used in the music video game Dance Dance Revolution : Mario Mix for the Nintendo GameCube .
Simplified: Mario Kart 64 is a racing video game made by Nintendo for the Nintendo 64 game console . It is the sequel to Super Mario Kart , and features eight playable characters .