Mosaic Heroes is a highly rewarding pixel art RPG game that features idle gameplay. You play as the executor of the Goddess of Light, tasked with stopping the demon race from awakening the Lord of the Demon Realm, Kantas. You must save the turbulent magical world of Emon by recruiting and befriending heroes from various races who possess unique skills. You can form your own team of executors and thwart the conspiracy of the demon race. You can also explore the unique story behind each hero and experience an epic storyline.

The game offers idle gameplay where your executor team battles automatically, and a bounty system that allows you to quickly claim rewards. You can collect offline rewards with the help of divine pets. There are many rewards and bonuses to be earned, including a sweet milkmaid for signing in and a magic core girl for your first top-up. The game features 40 heroes with different factions and positions, as well as skills and runes that can be combined in various ways to form unlimited strategic possibilities. The game also offers a variety of gameplay modes such as battles, collections, and development, and allows you to unlock the background stories of the heroes.