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