MischiefMaker: I gotta say, of all the developers out there, Cactus is probably the one I'd least expect to have trouble meeting a deadline.
HM is not a prototype, it's not one of his "crazy" game who can be have bugs and be patched a few days later because it's just played by a niche (and hell, it's free, who would complain about it), this time Cactus needs to make super-sure he's providing a 99% bug-free experience to people:
a) Because HM is probably going to reach more people than his other free games, so these people might not be ready or capable of dealing with bugs
b) Because these people paid some money to get it, so they'll get angry if it's too bugged (I know these people would be crazy, but well, they haven't played any other Cactus games yet)
c) Because it's a "bigger" game, so there's much more potential bugs to fix
The good thing is the guy is probably working on it now, unlike the big studios devs, who were so much into crunch, and with so much bureaucracy to deal with, that bug fixes take a week when it shouldn't take more than 48 hours.