Here is the full list of all 30 Apotheon achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Beat game on Olympian Difficulty
Access the sunken wreck of the Euphemia in the Sea.
Find all lockboxes on Olympus.
Acquire the powers from all twelve Olympian Gods.
Aquire the Sandals of Hermes.
Root out the assassins in the Acropolis.
Access the Gold Mine in the Sea.
Aquire the Kantharos of Dionysus.
Find all rare weapons on Olympus.
Access the Assassin Stash in the Swamps.
Aquire the Cestus of Aphrodite.
Access the Secret Grove at the Shrine of the Nymphs.
Access the Refugee stash in the Forest.
Meet the Necromancer in Hades.
Access Apollo's nectar cellar.
Access the Symposium of the Sun in Apollo's hall.
Acquire the Thunderbolt of Zeus
Acquire the Trident of Poseidon
Aquire the Artifice of Hephaestus.
Access the Merchant Stockpile in the Acropolis.
Acquire the Aegis of Athena
Access Kleio's gift in the Acropolis.
Acquire the Crest of Ares
Acquire the Sheaf of Demeter
Access the Hunter's Trove in the Forest.
Access the Agora Armoury.
Acquire the Lyre of Apollo
Access the Agora Market Scroll-keeper’s Office.
Acquire the Bow of Artemis
Ascend to Mount Olympus