Four Against the Titans (2018)

A stand-alone solo/coop pen and paper adventure game based on Greek mythology.
—user summary

Four Against the Titans is a pen and paper adventure game designed for solitaire or RPG-lite co-operative games. Set in ancient Greece in a time of myths and legends, players choose heroes from ten different character types to complete mighty quests and battle creatures such as centaurs, harpies and maenads, all in an attempt to defeat the titans and forestall the destruction of Greece.

Based on the Four Against Darkness series of dungeon delving adventures, Four Against the Titans is a standalone game. You don't require any other rule sets to play this game.