8 of them have already been added by Nintendo themselves.
I only discovered this a week ago but when you play the 'Platnium Cup', the 8 courses you race on are in fact courses from the F-Zero SNES game.
The courses are:
PLATNIUM CUP RACE 1 - Mute City: Multiply
PLATNIUM CUP RACE 2 - Big Blue: Big Billow
PLATNIUM CUP RACE 3 - Silence: Silence II
PLATNIUM CUP RACE 4 - Port Town: Great Wings
PLATNIUM CUP RACE 5 - Red Canyon: Red Canyon II
PLATNIUM CUP RACE 6 - Sand Ocean: Sand Ocean
PLATNIUM CUP RACE 7 - White Land: White Land II
PLATNIUM CUP RACE 8 - Fire Field: Fire Field
But you could remake the others!
