Apotheon is a 2D side-scrolling action game with puzzle elements and a visual design based on the Black Figure style of Ancient Greek pottery. The game is set in a world based on Ancient Greek mythology. The gods have abandoned the world and now the sea is without fish, the forest without trees and the earth without sun. Mankind has fallen prey to war to survive. The player controls the young warrior Nikandreos who fights the Olympian gods with the help of Hera.
Nikandreos needs to fight enemies and solve environment based puzzles to progress. He can pick up new weapons in the environment and many parts are destructible, providing new weapons that can be cycled through quickly, health, armour and coins. Coins can be spent to acquire better equipment. Weapons include swords, spears, bows, knives, javelins, stones, axes, hammers, slingshots, fire bombs and explosive traps. In later parts of the game different abilities of weapons often need to be used quickly in succession. For most of the weapons there are improved versions that can be located with additional abilities.
The level path is not linear and it is possible to explore in different directions, akin to an open world where Olympus acts as a central hub. Through a map different types of objectives are presented and these can generally be tackled in any order. The main quest consists of completing several domains, one for each god, split up in multiple smaller levels. Information about the different gods and their motives is often provided through stone steles. There are often side quests and optional objectives. The domains for the different gods include Apollo, Ares, Artemis, Athena, Hades, Poseidon and Zeus while the main locations are the Acropolis, the Agora market and the Olympian Gate. There is no experience system to level up, but a steady increase of weapons proficiency and armour strength through purchases.
The game has three difficulty settings and supports local one-on-one multiplayer where two players fight duels in small environments.