Download size

How many GB is Prime Directive?

16 GB

That is more than the typical Simulator game, which needs about 4 GB.

Leave at least 25 GB free: games need headroom to unpack updates.

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

Marty has crash landed on an alien world. He must escape, but can he survive? Guide him through interconnected environments and fight off hordes of alien creatures while you discover what happened to the abandoned human colony.