This game does exactly what it says on the tin. It has lots of battles. And they're in space. And they're completely gratuitous. No plot or characterisation to get in the way. Just lots of lasers and explosions.
The ships are beautifully designed. The graphics and special effects are glorious. And while the sound effects are a bit quiet compared to the rest of the game, especially when zoomed out (which is also not that good - not possible get the entire map into view), they are still as epic as you'd expect building-sized missiles and highway-thick lasers to sound.
That said, this game is not without its flaws. The zoom function, I've already mentioned - sometimes, you want to get an entire battle into view, just to see the sheer scope of things. Not possible, however. Fighters have little love in this game, having the smallest amount of customisation options. It is also quite easy to unlock everything, myself having done so after the first eight or so battles.
I've read some of the other reviews. They complain that despite the vast amounts of customisation, the battles are not conducive to that, instead forcing players to stick to the same narrow tactics, strategies and loadouts, in order to win. This is not true. Admittedly, it is possible to win that way. However, the real difficulty in the game is abandoning your OP strategy, and trying to win with your favourites, rather than the "proper way". Is it difficult? Yes. Is it frustrating? Yes. But, that is half the fun of the game.
Other people are giving negative reviews, because they missed the point of the game entirely. They were expecting an RTS, and what they got was something completely different. You are not a fleet admiral. You are not on the battlefield, commanding your ships. (Well, unless you select the 'direct control' button). What you are, is the guy on the space station, outfitting your faction's ships before the battle, then giving orders to the captains of said ships. You are the guy whose job it is to make sure as many of your guys come back. And doing it within a budget.
As to the people who complain about the cost of the DLCs. So what? You don't have to buy them. And if you paid attention to the developer's website, you'd know that the price is due to the cost of getting the new ships designed - The developer does not create ships himself, instead hiring a 3d designer from out of house, and contracting it to him.
One nitpick I do have though, is that the 'Complete Pack' on Steam is anything but, since it does not include the Parasite or Outcast factions.
In conclusion, a beautiful game, with some flaws, but nothing that should put you off getting it. I've had hours of fun with this game, and it has infinite replayability.