The biggest issue I've seen right now is that only the person who created the game can launch it, so if a game is created then the owner leaves it for some reason, nobody can ever start it even if enough players sign up.
For the "four legged beast or machine", you need to win it by beating the legendary horseman in a race, then just waltz into the train station where the horse will be waiting for you.
Oh, and to everyone asking for an easy way to identify which buildings have lots of zombies, click the layered green/yellow/red squares beside the little graph drawing. Buildings then get highlighted in red if there's lots of zombies, yellow if there's some zombies and green if there's none.
I would like to suggest the following: 1. Ability to filter survivors by ranks in certain skills (eg, leadership 5 or more and soldier 2 or less. 2. Individual happiness ratings for each survivor (sure, the fort as a whole might be happy, but when you've got over 100 people, there's bound to be at least one guy who's a little ticked off). 3. Relationships between survivors (inherent ones like family relationships and developed ones like friendships - could tie in with suggestion #2).
OK, this is weird. My previous high score on hard mode starting at 100 speed was 905. By holding down Q, I get a new personal best of 968. Moral of the story: really do a barrel roll!