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