Here is the full list of all 16 Planet Explorers achievements.
Survive to the last minute
Gain all the achievements
Complete the mission A World at War
Achieve Cordial in each party
Complete the mission Finding Malik
Nuclear explosion
Destroy all the towns
First ride on the monster
Collect 1000 currency
Complete the mission Set up a BaseCamp
Complete the mission Into the Desert
Complete the mission Bury the Dead
Collect 50 monster feces
Take over the mission The Forest
First recruitment
Complete Escort Mission