Here is the full list of all 12 Catastronauts achievements.
Achieved 3 stars for every level in the sixth hub
Rescued Sarge from Zastral's grasp
Completed the fifth hub
Achieved 3 stars for every level in the fifth hub
Achieved 3 stars for every level in the fourth hub
Completed the fourth hub
Completed the third hub
Achieved 3 stars for every level in the third hub
Completed the second hub
Achieved 3 stars for every level in the second hub
Achieved 3 stars for every level in the first hub
Completed the first hub