Download size

How many GB is Citadel Zero?

0.49 GB

That is less than the typical Strategy game, which needs about 3 GB.

Leave at least 6 GB free: games need headroom to unpack updates.

The figure is the storage Steam lists as required for this game, not a measured download.

Defend the last citadel on a dying alien world. Summon a gacha collection of bio-engineered defense towers, forge a custom loadout, and conquer three modes, story-driven Chronicle, roguelite Contracts, and 1v1 PvP Ascension. Tower defense meets deck-building meta-progression.