I Just bought this game, and I was really looking forward to playing it in multiplayer. I knew that local co-op wasn't supported, but then I did some research this morning I found this post here. I'm glad I found it, because this made me buy the game finally.
I just wanted to say that I agree with Tibbisan, I hope that the menu will offer access to local co-op natively later, not just via an official "hidden hack". But meanwhile, the "hidden hack" works just fine. The only problem I spotted is that, in my monitor is impossible to play two instances of the game with windows 2x the original size, and the original size is just to much work for the eyes. It's tough to read and just too small. It would be nice if there was a more flexible option for windowed resolutions, because the native original windowed resolution of the game gives me just too much unused space on my desktop, I could definitely make my windows bigger, but not 2x the original size tough.
Anyway, thanks for this game, I'm having a blast so far with my brother