Addictive stuff, can't wait for the full version!
I also liked the easter eggs, and little references to popular Youtube personalities (Clint and Freddie ftw!) and other video games (Gordon Freeman's Crowbar).
People have commented on the difficulty but I found it to be ok, a gun and run approach worked particularily well for me. Once you have upgraded your weapons and leveled up a few times, most missions can be soloed fairly easy, allowing you to get more done each day.
A few problems I had were (As previously mentioned by other posters), the revival system, a lot of the time a character would start to die just before I was about to transition to the next screen, forcing me to leave them behind, halfway through a revival attempt. A option to continue on to the next area would probabally be better, rather than automatically advancing.
Secondly I noticed in the options menu there were boxes to toggle autopause and grid on/off but they don't actually seem to work. Am I to assume this will be implemented in the full version, or have I just stumbled on to a bug?