Is now in beta. Similar deal to M&B, if you buy now you get the beta version and free updates up until the final release.
As the name implies, it's all about the battles. There's no overarching campaign, story or similar, just your ability to design a ship
Choose a battleground
Deploy your ships
And watch them shoot seven shades of ****e out of the enemy
The battles themselves are non-interactive, like Dominions and similar you deploy your fleet and give orders at the start of the battle and your ships will try their best to fulfill them. This allows for asynchronous multiplayer via play by email, and the ability to create or complete challenges set by other players (they create a kickarse fleet, you get to try to take it down).
There's no storyline, campaign or similar holding it together, just as the name suggests gratuitous battles. You do earn honour based on your performance in each battle which can be used to unlock new equipment for the designer. In addition, the game features four races which you can switch between after beating all of the battles for one particular race.
The ship designer is well done, with multiple hulls, weapons and other systems each with their own advantages and disadvantages. You're constantly balancing crew and power requirements and production with defence and offensive capabilities, with weight and thrust playing a part too. There are only three different classes of hull, however the variation in specific hulls along with the multitude of components allows for a lot of variation on viable tactics and fleet compositions.
All in all, it's a strangely compelling game.