Here is the full list of all 47 Ancient Planet achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Build 50 missile launchers
Save the planet from the democracy lantern
Destroy Emperor's pedestal
Build any 500 towers
Stop Phoenix
Demolish health obelisk
Build 20 support towers
Destroy 10 000 enemies
Free Aludrians from 200 jellyfish
Kill 500 doctors
Collect 50 000 silver units
Collect 1 000 gold units
Demolish armor obelisk
Kill one reanimator
Save the planet from 20 reanimators
Stop the incubator
Demolish any 200 objects on the map
Demolish attack obelisk
Shoot down 10 storm troopers
Shoot down 150 storm troopers
Demolish speed obelisk
Brew up 100 tanks
This honorary rank is given for 30 000 killed enemies
Kill 300 spiders
Build 80 factories
Crash 100 destroyers
Destroy 5 Aludrian mines
Build a support tower
Destroy any 50 objects on the map
Build ten energy towers
Kill 100 doctors
Collect 20 000 silver
Abolish any 10 objects on the map
Collect 200 gold units
Send to the skies 2 000 enemies
Kill 300 scouts
Build any 50 towers
Send to the skies 150 Aludrian officers
Destroy the destroyer
Raze the fallen missile to the ground
Kill 1 000 enemies.
Kill 150 troopers
Kill the first Aludrian!
Build one energy tower
Build three factories
Kill the first attacking Hamalian!
Build two machine-gun towers