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