Ten years after a mysterious incident during the first failed exploration of the Black Zone, humanity starts a second attempt. The player takes control over the small expedition troop under the command of Dr. Willow Burke, but of course everything goes wrong. It starts with an attack from some pirates and everything goes only downhill from there...
Ancient Space is a real-time strategy game which, similar to the Homeworld series, uses all three dimensions for unit movement. However, each of the 15 campaign missions is set in a relatively small area and features only a few (about two dozen) units at a time. The 15 ship types have different abilities (e.g. creating a protective shield or capturing enemy ships) and are especially effective (or ineffective) against certain other units. At defined points on the maps, the player can construct buildings (e.g. defense towers, repair stations or a detector for hidden enemy ships).
The most important unit is the main ship Ulysses II which is used to build new ships and has some special abilities. Between missions the player can choose the crew of the Ulysses II (which change the available abilities) and upgrade unit types. Upgrade points are earned by finding hidden artifacts which can be found with the Rover unit's scan function.
Besides the campaign there are three skirmish maps, but no multiplayer modes, available.