It's a pretty old space rts (created in 2001 I believe) where you try and defeat your enemy in a map made from up to 16 different solar systems, each connected by wormholes. There are three factions you can choose, and each seem to vary quite a bit-- you can choose the Terran, a balanced, human race; a high-tech, alien race which seems to focus more on big lasers and damage, and another alien race which seems to focus much more on fighter carriers and tactics. Each race is pretty distinct from the other.
What makes it stand out to me is the resource collecting-- while the combat can get pretty intense, I really like how each solar system has a limited amount of resources, often forcing you to expand out into other systems. These frontier systems are almost always (at least in my games, and even at 'normal' difficulty) frequented by large battles as each different faction attempts to gain a foothold.
Not only this, gas clouds, a resource which can often cover large portions of a solar system, can at times directly affect a battle-- many of them effect ships going through them, either giving them a speed boost, slowing them down, tearing away their shields, etc, so they can be pretty important strategically.
Also, while it is possible to just left click+drag to get a group of ships to attack, you can also make fleets with "admirals" that you hire from a certain building. All ships in this fleet not only get certain direct bonuses from being in the admiral's party (ie higher attack power etc) but also make the ships target faster, and generally fight smarter. Here's a quote from ign which explains it a bit better:
"when you normally order your ships to attack the enemy they'll attack the one pointed at, but then will clumsily find their next target unless specifically ordered otherwise, thankfully your enemy will fall under these same rules (no perfect computer cheating here). With an admiral (whom will take command of the largest ship in the fleet, so watch that one), on the other hand, your fleets will now react intelligently to the opposition, prioritizing targets, covering one another, and falling back when applicable. Just drop them in a zone, give them a general order, and watch them go, allowing you to focus your attention elsewhere."Oh! And it's got multiplayer too.
Hm.. That's all I can think of right now. In short: it's fun