Battlestations Pacific (BP) is the sequel to the earlier Midway title, which I admit to getting about halfway through before giving up.
I think the most important point potential end users need to be aware of is that despite all the hype about strategy, this is primarily an action orientated shoot-em up. It is most emphatically not Silent Hunter with surface vessels or EF2000 with WWII propeller planes.
For the single player you are offered a choice of two campaigns, either playing as American or Japanese forces. The American campaign is a straightforward re-enactment of key battles in the Pacific theatre between 1942 and 1945. The Japanese campaign on the other hand is supposed to represent a "what if" scenario, had the war followed a different path and the Japanese forces achieved a land invasion of the mainland USA. Sometimes it is fun to play as the bad guy, as those of us who enjoyed Tie Fighter far more than X-Wing will testify. However be under no illusion that what you are presented with in either scenarios is other than a set of pre-scripted missions, in no way approaching the dynamic campaigns of long gone but fondly remembered 90's flight sims.
I've currently progressing well in both campaigns. Each mission gives you a number of primary objectives to accomplish, some secondaries and the occasional hidden objective. However again it's important to note that you are prettymuch expected to follow the pre-determined path conceived by the level designer. If you go off to pursue a secondary task and in the meantime one of your other units manages to get the primary then you are rudely interrupted by a cut scene and skipped forward to the next "set-piece" or even ends the mission. So you don't really have that much freedom to go about on your own initiative. The action is good fun and combined with the graphics and sound effects is quite immersive. More often than not though, it becomes a simple slugging match between you and the AI rather than a tactical cat and mouse.
A quick word about the interface. The game can be controlled by either Mouse/Keyboard or X-Box 360 controller for PC but note not both at the same time. This leads to frantic scrambling around in the options during missions as the KBM is preferable for controlling surface units while the joypad is better for aerial engagements. As the game has a habit of switching you from a naval unit one minute to a plane the next this gets a tad annoying. Best learning how to fly with the mouse. Physics by the way are grossly simplified and, at least on Regular setting, you have virtually unlimited ammo.
From time to time the game expects you to take command of the strategy but trying to do this from the map or support screen while piloting a bomber on a torpedo run is not exactly easy. The interface is decidedly fickle. At one moment in the battle you can only give commands to certain units but then without warning they are suddenly available to you. Likewise clicking on a unit in the 2D map may (though not always) transfer you - most inconvenient in the middle of combat as you need to faff about re-opening the map and trying to get back on the plane or ship you were controlling a moment ago.
As regards DRM, you need the disc in the drive and the game connects to Windows Live requiring you to input the serial number. I'm not sure if that is a mandatory requirement to run the game standalone as my Live runs automatically.
In conclusion BP is a reasonable game and I'm giving it 3 stars. Just remember it is not the dynamic/strategic wargame the box might have you believe.