Here is the full list of all 32 ARK: Survival Evolved achievements. It takes around 200 hours to unlock all of the achievements on Windows.
You rode on the back of a T-Rex!
One of your Dinosaurs reached Maximum Level!
You Survived a full day and night on the ARK!
You Tamed a Dinosaur!
You Rode a Dinosaur!
You found the Dossiers of each of ARK's initial Specimens!
You defeated ARK's first Guardian!
You personally retrieved all the Artifacts!
You defeated ARK's second Guardian!
You defeated ARK's third Guardian!
You've defeated ARK's three Guardians! And yet...
You reached the Maximum Survivor Level!
You rode on the back of a Giganotosaurus!
You uncovered more than 80% of the Mini-Map!
You've reached the highest mountain peak of the ARK!
You've reached the bottom of the ARK's oceans!
You've cured yourself of Swamp Fever!
You Ascended off the ARK, at Gamma level!
You Ascended off the ARK, at Beta level!
You Ascended off the ARK, at Alpha level!
You discovered 10% of the Explorer Notes on the ARK!
You've discovered 20% of the Explorer Notes on the ARK!
You've discovered 30% of the Explorer Notes on the ARK!
You've discovered 40% of the Explorer Notes on the ARK!
You've discovered 50% of the Explorer Notes on the ARK!
You've discovered 60% of the Explorer Notes on the ARK!
You've discovered 70% of the Explorer Notes on the ARK!
You've discovered 80% of the Explorer Notes on the ARK!
You've discovered 90% of the Explorer Notes on the ARK!
You've discovered 100% of the Explorer Notes on the ARK!
You tamed all of the domesticable creatures on the ARK!
You defeated the Guardians of The Center!