nicmhp2: I cannot find any mission in the "Missions" tab. Should I download from somewhere else or I need completing any stage in order to trigger the build-in missions? Thanks for your help.
Theoretically you just have to download a custom mission to Etherlords 2\Maps\Custom folder and then you should be able to play it. I said "theoretically" because some time ago I tried to find some missions and didn't find even one of them! There is an editor so I guess you can create one yourself but frankly, I've never used it so I don't know if it's good or not. Anyway, definitely you don't need to unlock anything. And if you find some missions to download please let me know :)