As I mentioned Monday in my preview of Multiwinia there’s going to be online co-op included in the title that launches “this fall”. I contacted Introversion to clear up the details and here’s what they had to say:

We’re due to launch on September 19th. There will be a vast choice of competitive maps available to play across the 6 modes and co-op maps are available on three of the game modes. Maps will range from 2, 3 to 4-player – all the co-op maps will be 4 player.

That date is confirmed for the PC launch on Steam, UK retail and their own store. Darwinia+ will be hitting XBLA later this year and they’re still trying to nail down retail releases outside of the UK. We’ll check back in when we find out more.