It is set primarily on an archipelago of islands in a fantasy world, where the player controls either Valere or Zale, Solstice Warriors who use the power of the sun and moon.

They journey throughout the world on a quest to destroy powerful monsters called Dwellers, and to stop the immortal alchemist who created them.

The game is presented in a fixed isometric view using two-dimensional pixel art, similar to Super Nintendo Entertainment System-era RPGs such as Chrono Trigger (1995).

Creative director Thierry Boulanger's vision for Sea of Stars was to combine what he saw as the best parts of several older role-playing games, with an emphasis on modernizing and translating the feeling of playing them rather than directly copying them.

The studio wanted to self-publish, and launched a Kickstarter campaign in March 2020 alongside a press reveal to prove the viability of the project to themselves and investors.

[1] Both of these are presented in a fixed isometric view using two-dimensional pixel art, similar to Super Nintendo Entertainment System-era RPGs such as Chrono Trigger (1995).

In the navigable areas, the player can converse with locals to procure items and services, solve puzzles and challenges, or encounter enemies.

[3] Outside of battles, the player can interact with non-playable characters, who can have short conversations, sell armor, weapons, and items, and give quests.

[7] Puzzles are required to be solved throughout the game, usually by moving blocks, flipping switches, and using Zane and Valere's Eclipse magic to adjust the time of day.

The four track down and defeat the Dweller alongside the other Solstice Warriors—Erlina, Burgaves, and Headmaster Moraine—after which the former two betray the group and summon a cult serving the Fleshmancer.

In response, Resh'an began training the first Solstice Warriors, sparking a conflict between the alchemists spanning countless parallel universes.

The conflict continues in each universe until the Dwellers grow into apocalyptic beings called World Eaters, or the Solstice Warriors gain enough power to become guardian gods.

Resh'an agrees to fight by their side, but warns that he cannot engage the Fleshmancer's creations directly, leaving Valere, Zale, Garl, and Seraï to confront the Dweller without him.

On the verge of losing, Seraï attacks the Dweller with Resh'an's hourglass in desperation, and its power attracts the attention of the Fleshmancer.

The alchemist dismisses the Dweller, acolytes, and Brugaves to his lair, appoints Erlina as his lieutenant, and mortally wounds Garl before leaving.

Resh'an uses his power to temporarily extend Garl's lifespan, and the warrior-cook spends his remaining time helping the party secure passage through the Sea of Stars before dying.

They arrive at a technologically advanced planet, which Seraï reveals is her home; she had traveled between worlds to recruit Solstice Warriors who could liberate her people from the Fleshmancer.

The party fights through the planet alongside B'st, an ancient spirit given a new body by Resh'an, and they confront the Fleshmancer at his lair.

Learning that a World Eater is approaching, Valere and Zale gain enough power to become guardian gods, and they leave their friends to protect the universe.

Creative director Thierry Boulanger was interested in creating an RPG, but felt that it would be too complex for a studio's first game.

After the game won several awards and sold well, the team began development on Sea of Stars immediately following The Messenger's release in 2018.

[14] Similarly, composer Eric W. Brown created different ambient sounds for all of the areas to evoke a sense of place and connect the audio experience with the gameplay.

[16] The music was released as a three-disc digital album, Sea of Stars Original Game Soundtrack, as well as a 2-disc vinyl LP record.

[25] A free update to the game, "Dawn of Equinox", was released on November 12, 2024, adding co-op for up to three players, changes to combat mechanics, and a revised prologue.

[1][33][7] GamesRadar+ also criticized a lack of depth across all of "the mechanical parts" of the game, including the puzzles and side activities, though IGN said they were simple but required "a decent amount of thought".