Here is the full list of all 10 Return to the Skyway achievements.
Complete the first level.
Throw an animal 100 times.
Throw an animal 50 times.
Pickup the final missing ship part.
Pickup the second missing ship part.
Throw an animal 10 times.
Pick up Soos.
Pickup the first missing ship part.
Pick up Chad.
Outrun Bruno.