Here is the full list of all 15 Jettomero: Hero of the Universe achievements.
Collect all parts
Search for survivors in a pile of rubble
Prove you're the best of the best
Find a way to actually save the humans
Make a difficult decision
Unlock all back issues
Extinguish a forest fire
Land on a moon
Fly through all the rings
Destroy 25 asteroids
Catch a comet
Get real warm
Chase a storm away
Find a helpful lift
Find a purpose