Nice and Calm: Stop all of the turbines by finding the hidden switch
As you go over the first jump, flip forward to gain momentum then hit Y/Triangle to bailout and launch yourself towards the claw hanging on the far side.
Hold down Y/Triangle to grab the claw, and keep it pressed until you're lifted over the switch before releasing to drop down onto it and stop the turbines.
Greenhouse Effect: Stomp all of the flowers
Back up at the start to flatten the first flowers.
Ride slowly over the first peak to hit the second flowers on the way down.
The third flowers can be found by the side of the road.
For the final flowers, you need to bunny-hop over the stone ledge to stop it from collapsing, before backing up to squash them--you'll also get squashed too!
Wormholin': Use the afterburners to reach the portal in the sky
At the start of the course, drive slowly off the first ramp to land on the ledge below, then back up onto the afterburner to get started.
Continuously boost and try to keep your bike at an angle so you're moving forwards and upwards. Each ring you pass through gives you additional afterburner time, until you eventually reach the portal on top of the large quadcopter.
1-Up: Don't allow your front wheel to touch the area between the red lines
Wheelie up this red-sided ramp, ensuring your front wheel doesn't touch down at any point.
If your wheel does touch down, hit Return to Last Checkpoint to go back to the bottom of the ramp and try again--you can have as many attempts as you like.
Rider-Cam: Hit the gyroscope and complete the track in rider-cam mode
Reverse down the ramp at the start of the course and hit the gyroscope to enter rider-cam mode.
Now finish the track with the camera view switched behind you--note that the controls remain the same so you still need to push left/right to lean. A faultless run is not required.
One-Wheel Wonder: Don't allow your front wheel to touch the area between the red lines
Wheelie up the dirt banks after you see this red line, ensuring your front wheel doesn't touch down at any point.
If your wheel does touch down, hit Return to Last Checkpoint to go back to the start of the dirt banks and try again--you can have as many attempts as you like.
Secret Agent: Enter and navigate the top-secret facility
After jumping over the walkway with the red-striped hatch underneath, ride up to the next ramp to trigger an electric blast but don't jump off it.
Instead, back up along the track and fall into the now open hatch.
Now use the d-pad to navigate the maze, going through the green, blue then red zones until you see a white corridor with the exit.