| Be careful!
This level or achievement has been known to feature a bug. Please attempt it with caution.
To earn this achievement, use either the Skater or the Child (although, the Skater is a bit better), and move right at the start to cross the first gap. After that, you can get into the air by using ramps and/or landing on the sides of boxes. The Skater benefits more from ramps, and the Child benefits more from boxes.
Walkthrough 1: here.
When completing this achievement, even though you have met all criteria, the achievement window in the top right will not appear. Don't worry, you will still have earned the achievement. If you need to see if the achievement is completed or not, look in the achievement menu to see if it is completed.