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