This is directly off the workshop.
Duration
- Easy: prepare time 15 min, defense lasts 60 min.
- Normal : prepare time 12,5 min, defense lasts 60 min.
- Hard: prepare time 10 min, defense lasts 75 min.
- Heroic: prepare time 8 min, defense lasts 90 min.
There is a Japan Defense against the US, USSR Attack and/or Defense against the Germans (I've only done the defense side of that map), UK Defense against the Germans and finally German Defense against the USSR/UK/US.
I've yet to achieve maximum upgrades in the Heavy Vehicle side of things (that I'm aware of. Was too busy trying to hold the line) to know what you get. I have gotten high enough in the German maps to know you will have access to the Panther and Tiger I though. But it just made my run a tad harder. You have to balance it out. If you go all out into upgrading one section, you tend to pay for it heavily later into the map, if not right away. You'll notice supply trucks when you start up the map, if you want to win, you MUST defend your supply lines all the while trying to hold your HQ against the enemy. Adds some zest to things, that's for sure. Something that my not be mentioned though, with the Small Arms truck, you only need to get it close to your infantry and they will "auto resupply". But with the Heavy Arms truck, you will need to manually offload the supplies and take them to the gun you wish to resupply. So bare that in mind. I've managed to stick the trucks close enough to the infantry to keep the supplied, but far enough into cover that they don't get picked off by tanks (though they do take the occasional shot from infantry).
I've already commented in the workshop, asking if he intends to add a Japan Defense against the UK/USSR, UK Defense against Japan, US Defense against Japan/Germany, and USSR Defense against Japan. I'm about to check to see if he has responded himself or if some of the others have answered.
Last night a friend of mine and I took on the IwoHonda map. It's got a couple of issues, but overall is nice. Too bad he kept driving his tanks across the airfield, which at one point resulted in a couple of the "supply planes" crashing into the side of a tank. Plane AI, yeah, tad slow.

One bit he got a Chi-Nu hit by one, which tracked it. 2 More ended up rolling into it before he managed to get the track repaired and get it clear. That did stress the lines a bit, but overall it held.
The Defense maps are a very nice change from the standard that the game is currently in, Attack/Hold/Attack/Hold pattern. I know that there will be a Normandy map coming out soon, which allows you to play both sides. That one is going to be interesting, though I hope to see some changes to it. We'll see...