This is the first level of Homeworld 2, where you will be introduced to the Hiigaran Mothership, the Pride of Hiigara.
Testing the Mothership
After watching the movies and cinematics, the game will focus in on the Mothership's initial engine test, and Fleet Intelligence will introduce itself by telling you that you've got to test as many of the Mothership's other systems as you can before kitting it out properly and readying it for battle. Fleet Intelligence will be speaking a lot over the course of the game, and it always has important things to say so make sure you listen to it.
To begin with, you have to test the Mothership's resourcing operations. Select the lone Resource Harvester you have and have it begin moving the resource crates to the Mothership. You only need to get one 700 RU crate before the game will advance; there are a few 700 ones and a few more 200 ones amongst them.
Your next task will be to construct a Fighter Facility for your Mothership. This costs 500 RUs, and doesn't take long to construct. Once that's done, you'll then be asked to build an Interceptor squadron, which costs 200 RUs. When they're finished they'll launch from the Mothership automatically, and you can then use them to destroy the target drones that Chimera Station provides for you, so select your Interceptor squadron and right-click the target drones to send them to attack. When they're all destroyed, Chimera Station will report inbound Vaygr Bombers!
The Vaygr Strike Force
Unfortunately, this game will drop you right in the thick of it from the start. To begin with, send your two Interceptor squadrons to attack the Bombers as they approach Chimera Station. Interceptors are particularly effective against other fighters; remember this property, as it is one of the keys to a powerful fleet. In this case, your Interceptors will quickly deal with the Bombers. However, during the cutscene where the Mothership initiates an emergency launch from Tanis Base, several reinforcements appear, including a Vaygr Heavy Missile Frigate which will immediately begin attacking the Mothership.
Your two Interceptor squadrons are, for now, good enough to slowly take care of the numerous Bombers that the Vaygr have sent, so do as Fleet Intelligence says and build 2 Bomber squadrons. These will automatically begin attacking the Heavy Missile Frigate, which Bombers are particularly effective against. Once the two minutes are up, three Vaygr Hyperspace Gates will appear near Tanis Base, which Fleet Intelligence will instruct you to destroy. Send your two Bomber squadrons to deal with each of the Hyperspace Gates in turn, but as they appear, more Vaygr will warp in. Let your Interceptors deal with them; your Mothership, for the most part, has a passive repair rate which will exceed the damage that it will receive from enemy Bombers unless your Interceptors get destroyed for some reason. Damage will very quickly begin to stack after that, so watch out.
Build another Interceptor squadron to speed up the elimination of the various Vaygr fighters swamping Tanis Base and the Mothership, then just wait for the Bombers to get rid of the Hyperspace Gates, and your Interceptors to clean up the last of the Vaygr attackers. When this happens, you'll detect a large number of enemy signals. An entire Vaygr fleet will warp in, armed with Destroyers, Carriers, Battlecruisers and much, much more! Tanis Base will get wiped out, but just before your fighters will dock with the Mothership, and you'll escape via hyperspace to the Angel Moon.