played it - the one offered on the original site has more locations and weapons - i beat it too - had an army of 4 survivors with AK, M4A1, UMP45 and shotgun - I had the hunting rifle (1 headshot kill) and chainsaw for backup, last fight i had hand grenades that made the game way too easy
the chainsaw is incredibly good if you barrier gets destroyed as the last 3-4 zombies come to you (by then the survivors run away) but you can still hold off the zombies really well with the chainsaw