Wings of War arrived last night and I've played about two hours total, both in the campaign and Instant Action. There is no multiplayer - Instant Action is either you against up to 10 bots, or your ten man/bot team against another ten bot team in Team Deathmatch.
Anyway, I think this game really is a pleasant suprise, and though it doesn't have Live, I think the single player game is more enjoyable than the single player game of Crimson Skies in terms of action and combat. For one, there is a ton of stuff going on at once - you have your mission paramters (and there are about 7-10 goals per mission), you have a constant onslaught of enemy planes, you have bonus missions that unlock missiles(?!), health packs, secondary ammo (there is no limit on primary ammo, but you can set the guns to overheat). Another plus is that I felt some of the missions in Crimson skies were a bit too rigid in time parameters or objectives (i.e. stunts). Here there are time-based objectives, but those that aren't, and aren't protection missions, pretty much free up the map for you to explore, dogfight, and just enjoy yourself.
The menus are well done - there is a hangar which lets you see all the planes, and as you complete single player stages you unlock these planes for Instant Action. There are about 30 planes total, I'm guessing, and each plane has maybe 1-10 camoflage patterns (which unlock with the plane). The paint jobs aren't as useful as they might be on the PC version where you do have multiplayer, but there are some cool planes and patterns.
Your player file tracks score, time played, accuracy, and types and numbers of targets destroyed. You can also earn medals based on points earns and number of targets destroyed - the manual explains this in more detail. There is a High Score table that you can climb as you progress.
What I really enjoy is that during the single player campaign, the weather and time change (though I haven't yet seen a mission at night, if there are any), and the graphics, while nothing near as good as Crimson Skies, are actually all right -- you can fly low and see buildings, farm, moving vehicles, trees, trains, ships, etc. And low to the ground are where the bonus missions hang out. Your plane and the others distentigrate when shot at, and I've seen a few dead planes sticking out of the ground as I passed over. Unlike Crimson Skies, you can shoot down the parachutes of pilots who have bailed from their planes. They even give a little scream after you do so. Very fun.
The game is also fairly customizable in that you can set the flow of the camera behind your plane - either making it very rigid, or a looser "follow cam" as in Crimson Skies. You can decide if your guns overheat, how you control your plane (3 different setups), where you want manual contol over throttle. You can set your crosshairs to a color/style you like.
A nice tidbit, before I forget, is that you control takeoff and landing your plane as well, though that's a bit trickier.
I also think I prefer the open, more realistic environments over those of Crimson Skies. The first PC-based Crimson Skies was a lot more 'realistic' in its environments, I think, but this game goes for a nice, loose reproduction of WWI - I think too that the planes being a bit older adds some character.
I've had the game on while typing this and Demo mode just kicked in - UK biplanes against a German zeppelin. I really like that this game is similar to Crimson Skies, but more stright-faced -- the downside is that I have yet to encounter any real story, but I do like the pick-up-and-play style, and I can't wait to hit those Zeppelins.
So, for twenty bucks I'm very pleased. I think if you enjoyed Crimson Skies and want to try something different, give this a rent or go for the cheap pick-up. I am a big fan of games that don't require me to care much about them - waiting for save points, or needing to obsess over a level. I like to sit down, play for a while, and then go about the day. This is a great game that meets that sort of play style, and the sheer number of objectives, bonuses, and enemy planes makes this fun without the headache of completion that bugged me about Crimson Skies.
One caveat: it takes a while to learn the controls. It does not share the MS Halo/Crimson Skies control scheme, but there are three sets of controls to choose from and I've found "C" is the best for me. I do miss CS' many trick maneuvers - but these planes do feel more brittle.
Hope these impressions are helpful. Wings of War gets a Thumbs up from me!