Alternate views
Select time attack mode, choose any track, and enter "CAM" as a name. Hold L1 + L2 + R1 + R2 and press X at the "OK" prompt to confirm the name. Exit the track and press L1 to access three new views.
Bonus Area: Phantom Dish
In FUNGAL FREEWAY (while in TRACK ATTACK/EXPLORATION) you can go up to the stone wall. There will be to little ramps leading to the wall. Both are on either side of a door. Go up both ramps and when you hit the wall stop, this will push in two large bricks. Go to the door in the middle of the two ramps and run into it, this will make it open and you'll be in the bonus area.
Get power-up when you enter a gate
Enter exploration mode and complete three laps. Then, enter "POW" as a name. Hold L1 + L2 + R1 + R2 and press X at the "OK" prompt to confirm the name.
All gates unlocked ...