Here is the full list of all 35 PixARK achievements.
Open a highest level Chest in Ruins
Tmade a BabyTreant
Get a MolePick
Get a FlashStick
Now you have killed the strongest creature in this plant.
Take those treasure away
Explorered the DoomLand
Get something from the Supply Crate
Quetzalcoatius is the one you must needed
Get a good partner
Tamed a Sauropod
Killed a Large Sea Slime(Ruins)
Killed a Ice Fairy(Ruins)
Killed a Mummy King(Ruins)
Killed a Cyclops
Killed a Behemoth
A poor creature was killed by you
Rex is not the most dangerous animal,but you are
Dig the Ruins in Grassland and get a Ruins cube
Dig the Ruins in Frozenland and get a Ruins cube
Dig the Ruins in Ocean and get a Ruins cube
Dig the Ruins in Swamp and get a Ruins cube
Dig the Ruins in Desert and get a Ruins cube
Dig the Ruins in Swamp underground and get a Ruins cube
Get a ArmadilloShell Equipment
Get a Scuba Equipment
Get a Bamboo blueprint
Get a Weastern blueprint
Get a Mediterranean blueprint
Get a MagicAcademy blueprint
Get a Executive blueprint
Collected your first cloth
You are the strongest man in this plant