Here is the full list of all 10 Psebay achievements.
Stay underwater for more than 20 seconds (in total)
Fall off the motorcycle more than 50 times
Create more than 3 levels using level editor
Complete all levels of the chapter “Road of Psebay”
Drive more than 50m. in the infinite level
Drive more than 250m. in the infinite level
Tear off the front wheel more than 4 times
Get 3 stars at all levels of the chapter “Road of Psebay”
Drive more than 500m. in the infinite level
Drive more than 1000m. in the infinite level