Here is the full list of all 13 Sky Valley achievements.
Complete 4 levels
Complete 2 levels
Best Result: 1 000m
Fly 10 000m
Fly 25 000m
Fly 50 000m
Fly 100 000m
Fly 250 000m
Fly 500 000m
Fly 1 000 000m
Complete 8 levels
Best Result: 5 000m
Best Result: 10 000m