Foundation's Harvest Festival reaches Steam on 8 October 2026

Polymorph Games has set a release day for Harvest Festival, the first major expansion for its medieval city builder Foundation. It goes on sale on Steam on 8 October 2026, and the store page can already be wishlisted. The studio thanked players for the long wait and said the virtual harvest simply needed a little more time to ripen.

Farming in the add-on is much broader than in the base game. Players plant fruit orchards, sow new hardy crops and keep chickens, pigs and geese. The extra raw goods lengthen production chains, unlock cooking recipes and give villagers a more varied table.

Festival grounds sit alongside the farms. A celebration for the peasants has to be prepared by hand: food, drink and entertainment. A modest village gathering can be built up into a grand fair fit for a visit from the king.

A reveal trailer went out with the date. The add-on is listed on Steam as Foundation: Harvest Festival.