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