Mixed feelings about a possibly great game
First, don't expect this game to be a realistic representation of WW2 except for the first turn set-up. After that, all bets are off. I've seen lots of unusual actions by the computer that don't represent realistic war actions or acts that would be evaluated in the traditional WW2 political arena. For instance, USA will declare war on Germany in 1939 but not be a member of any alliance. Hungary declared war on Italy as did Japan in 1940. Britain tried several hopeless sea invasions of East Prussia. Yugoslavia in one game attacked Germany in 1939, China tried to ally with Germany while Japan and Germany were allies. In other words, expect anything.
Second, many combat options of WW2 are missing or skewed.
There are NO airborne troops at all so taking places like Crete or Malta are impossible against the Brits and their enormous seapower which tends to clump into huge killer stacks. The 'clumping' occurs, no doubt, because there is NO convoy system at all to protect. Subs are a useless item for any strategy and are mearly another 'type of surface ship' in combat which they probably won't even engage in unless they are part of a surface fleet. So if you have ideas of U-boat play - forget it.
Combat is not too particular especially with multiple enemies. For example, the US and the British alliance were at war with Germany BUT they were not allies and as such, in my opinion, the fleets and units should not be in cooperation with each other: yet, in any combat situation they were totaled as one combined attacker. It's not happened, but I could see a situation where the US and British alliance were at war with Germany AND each other - how would combat go then? This could apply to various other combinations as well.
Aircraft are lengthy and expensive to produce and get killed easily so you can quickly be without any at all. They are also oddly ineffective except for killing ground troops. I rarely hurt ships with my light bomber units even against surface fleets without any CAP. My fighters, even in stacks of ten, rarely detered small groups of enemy bombers from bombing my cities. The fighters rarely got any kills against unescorted bombers and often lost. In one case my 10 improved fighters met 4 pre-war fighters and 2 bombers and lost six for no effect.
As noted with aircraft, you must get used to combat being a "Risk game" mentality of your units mearly representing dice rolls and forget strategy and tactics. It's simply roll the dice and see what happens. You have some benefit of "better dice" with "better units" but any tactics of combined arms or modifyers seem absent.
So all in all, whether at sea or on the ground, combat is you build units, put them into big stacks and attack where the enemy isn't. Once I realized this, I started a game as Germany and slaughtered Poland by putting everything in one stack and going area to area while "single units" took the empty areas. I lost two units in the whole campaign and realized the way to kill the enemy is too give him no where to retreat. The first time I played, I tried the blitzkrieg tactic and got hosed.
So forget Blitzkrieg, convoys, sub warfare, air transport, paratroopers, engineers, strategy and the like.
On the flip side, what this game becomes is a great "beer and pretzels" nailbiter as you try to score more points and/or take over enough of the world to win the game in classic Risk style. You do get a little flavor of diplomacy (get others to chip in help), research (better die rolls in effect), trade (get more guns and butter with your cash) and production (build your units) but it's all geared to getting your side to beat the 'other' sides.
So for grognards, you should probably take a pass and stick with HOI2, SC2 or similar attempts at WW2 strategy games and for everyone else who just wants to play a really cool game of Risk - this one is for you especially in multi-player fashion.