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