Unlock the final track
First: B grades on all the tracks in Excite Mode. That’ll unlock the tougher Super Excite Mode. Then - you’ve guessed it - grab B grades in all the Super Excite tracks. The Diamond Cup’s single course - Nebula - awaits.
The bestest, longest shortcut…
… is on Canada (Gold). Race up the really steep hill, veer right to land in the water for a mighty Air score, steer back up, take a hard right through the “!” (shown here), land on the POW, then race the super-high mountain tree run.