It's not really a flight sim, far more focused upon the combat, and oh boy what combat that is.
This game is by far the most planes I have seen all fighting at once. You take part in huge battles (not you SWON or Crimson Skies 10-20). Huge battles = lots of targets, and lots of action.
It's not all about dogfighting, there is also bombing, and torpedo bombing, I'm enjoying the dive bombing most.
On the negative side, the game is fairly tough to start with, you do need to read the mission briefings to know what's going on.
Also some of the voice acting is a bit cheesy, but in a way it fits, the menu art is all done as old war posters "Your Country Needs You" kinda stuff and is pretty cool in a cheesy way (take a look you will see what I mean)
There is also a multiplayer game, which seems pretty smooth for the PS2, so all in all a great package if you are a fan of WWII.
Plus there are heaps of planes to unlock, and you can retry missions with the new planes, so experiment with a whole load of 'what if' situations, such as if I you had a Bearcat at Pearl Harbor. Going to be playing for a while now.