Yshinozuka: If you're into World War I, I'd definitely recommend Rise of Flight. I had been very hesitant at first to buy it, mainly because it seemed to be lacking in content, and I was at first displeased by the fact that you have to pay for more planes, but a recent patch has added a campaign, a quick mission generator, and an offline mode. Modders have also been working on a dynamic campaign generator similar to Red Baron II, and the developers are working to get community skins incorporated into the game. I haven't played the multiplayer yet, though.
When you see the amount of detail and authenticity put into the planes, the four that come with the game can keep you well occupied as you attempt to master them. And I'm really glad that the developers aim to improve the game and enhance the experience you paid for, while funding it through optional planes. If they charged for plane skins, that would be ridiculous. Sorry if it appears that I'm trying to sell you the game haha, but it really exceeded my expectations.
Edit: Sorry, I missed what you wrote about WWI, but I suppose this post is for anyone else.
Thank you but I am not touching anything with extreme DRM.