Expedition 33 developer Sandfall Interactive was formed after the game's director was bored at his job at Ubisoft. He started recruiting on social media to create Expedition 33. He found the lead writer on Reddit and the composer on Soundcloud.

Game director Guillaume Broche detailed how the project wouldn’t have been feasible at a bigger studio in an interview with Pouce Cafe.

Expedition 33 is set in Lumiere, a fictional world overshadowed by a huge monolith bearing a glowing numeral on its face. Each year an entity known as The Paintress emerges and lowers the number by one, causing everyone of that age to vanish, and the game follows a group on a quest to destroy the mysterious being.