Well there's not much information about EoD-3, just a few screenshots (and they're not really good).
The game's website will be released very soon and it will come with tons of stuff though the game is still not finished.
The plan is to have a download (something about 1.0 - 1.5GB) and maybe a DVD box. You buy the game once and get every update/extension for free. The license will be personal for the player's PC and notebook/cellphone/pad but not for the whole family
I'm not sure how to sell the game. It's hard to get a webshop online and get all the payment methods working.
And finally all the legal stuff. German law is restricting everything. This is the land of
Keep of the grass!
OS: Win XP, 7, 8, Linux, Mac, perhaps a (smaller) browser version and perhaps Android, xBox, PS4 & Co. at a later time.
Coop: very difficult and a lot of additional work. I tried adding some bots but I'm not happy with it. Maybe they will not be in the first release. EoD is primary a multiplayer game and the bots may wait a little bit.
DRM: not sure but the game will run 100% offline. If the first release will come without AI you'll not be able to play everything, just the SP part.