Here is the full list of all 14 Children of the Galaxy achievements.
Acquire 200 technologies, across any number of playthroughs
Explore 333 systems, across any number of playthroughs
Get 50.000 energy, across any number of playthroughs
Colonize 26 planets, across any number of playthroughs
Get 10.000 energy
Colonize a planet
Scan 200 systems, across any number of playthroughs
Acquire 10 technologies
Explore 10 systems
Scan 10 systems
Win a game
Expansion Victory
Domination Victory
Research Victory