This is a really fun game. They are doing a free Beta right now, and I have been having a blast. The graphics are rather simplistic, which is ok since that makes it easy on the system requirements, but the game is rather addictive, especially for fans of naval games.
You start out with a frigate, and as you gain points/money, you can upgrade the systems on your ship, or buy a better ship. You also recruit crewmembers which gain experience. As they go up levels, you can eventually pick bigger ships (all the way up to battleships and aircraft carriers).
The controls can be a little tricky, but after you do the practice missions you can become surprisingly accurate. There is an auto-aiming Fire Control System, which allows you to simply click on a part of the screen and have your guns aim there, but overall it is actually more inaccurate than simply familiarizing yourself with controlling the turret direction/angle. And if you are totally hopless, you can always do torpedo runs (slow, but high damage, and it is funny to see ships instakilled when they are hit by 3+ torpedoes at once )