Same characters, same kart, same engine class, in the Flower Cup. As seen in the last race, those Blue Shells can screw you over, but they sure can help you.
Tracks:
Mushroom Bridge (reappears in Mario Kart DS)
Mario Circuit (reappears in Mario Kart Wii)
Daisy Cruiser (reappears in Mario Kart 7)
Waluigi Stadium (reappears in Mario Kart Wii)