Starbase Aggression
The best part about Starbases is that they aren't all defense. If you can establish a beachead in enemy space and get your construction ships busy, you can crank out a massive Starbase right on their doorstop. Not only is the firepower going to chew through their ships like a blender tearing through wet cheerios, the Starbase will be sitting right on the jump lane - letting you retreat/reinforce your ships freely while your opponent panics. This will be even more effective for the ship-boosting Advent Starbases.


Now, let's not get started on the cultural impact of Starbases. Or, what the heck, lets.
Got Culture?
Not only can Starbases beat spaceships silly, having a monolithic military presence in space affects nearby planets. They have a strong bolstering cultural affect on your ships and citizens. The presence of a Starbase is so powerful that your opponent won't be able to convert or colonize any planet in the same gravity well unless they destroy the Starbase first. And, well, good luck with that. One note though - this power is still being tested. It's 95% guaranteed, but might be tweaked before release.
Mine, Mine All Mine!
Mines are another addition to Sins. They let you decorate your gravity wells with sneaky explosive death and cause attackers all kinds of trouble. Most ships can't see them until it's too late. But, Scouts can spot them in time for your ships to blast through them unharmed.
Upgrade Everything
On top of Starbases and mines, Entrenchment also brings new upgrades for other facilities. Gauss cannons for instance get two. The first is Burst Rockets, short range weapons with a rapid rate of fire that hit four targets at once for low damage. The second is the Meson Bolt Cannon, a high-damage weapon with enough range to be able to reach the edge of the gravity well from the buildable area. The Meson Bolt Cannon is also an armor debuffer, making targets vulnerable to other attacks for a while.
That's just about it for game details, but we have more about Ironclad, the single-player Sins expansion and, of course, something special for the Space Ponies.