The defense method really blows - it's pretty impossible to survive past a couple of days since the people move too slowly to get enough materials for building heavy defenses, and the shooting-zombies-one-by-one is awful. Cool concept, cool graphics, needs work.
The controls for this game are just a little bit rubbish... It's pretty difficult trying to use both keyboard and mouse to control the character. Personally I'd prefer just mouse, with a left click indicating where the character and pet should go, and left click on an enemy to engage attack or pick up items.