Yeah in the Galactic Annihilation, I've discovered that you need to collect tech from either conquering or exploring systems. To build advanced vehicles and subsequently tier 2 technology like advanced power stations and orbital lasers you need to either have the corresponding advanced or complete (if you don't already have basic like naval)
It can be interesting, but you seem to need to be lucky in what you loot, I was fortunate enough to loot super weapons but don't get too excited, most bouts are over before you have chance to complete construction.
Problem is, core matches where you're attacking an enemy core world (will have their little symbol on) are near impossible unless you're packing 2 sub commanders as you can be expecting to tally up against 2 or three enemies on a large system (3 or 4 planets) those so far are the only matches I've sort of enjoyed and I finally even got to use the "Halley" (Planet engine) to fly a moon into a planet.. That was pretty fun! Though crippled me too as most of my resources where coming from that moon.
Best technique I've found for winning a 1 on 1 against the AI though is to build 2 metal extractors and power plants for every 1 factory, for ever 1 factory build 2 construction units build some defenses and then rinse and repeat while churning out tanks and anti air etc and start flooding!
I am pretty disappointed by this game though, yeah compared with say the old Command & Conquer type games there are a few new features, yeah you can hop planets, yeah you can smash one planet into another and the maps are spherical as opposed to flat and you have no unit cap (though build to much and watch your fps drop to a slide show). Oh and they seriously limit your tech which could be kind of cool if it was better thought out...
But there is nothing really new here, there is no space combat and never will be apart from building a few satellites, systems you've secured never come under attack and from what I've seen they never will, so you don't care about the systems you capture and it just feels like one skirmish after another with no real objective or reason.
I hate to say it but despite the hype this game has generated its not the RTS we've been waiting for... and I much preferred playing Supreme Commander 2 and Total Annihilation to this.
Okay so cross Planetary Annihilation, Empire at War (for the space combat) and Total war (for the campaign) but have it so capturing, holding or destroying worlds or even entire solar systems is actually important and that the ground game is equally as important as the space game and then you've got a truly epic or uber strategy game I'd gladly shell out a ton of money for (if I had any)