The Filler can be a challenging, fun game when players act as the titular character, but the enjoyment of the zombie player's role seems largely contingent on the person playing. Admittedly, this is probably because the two roles are not perfectly balanced: The zombie player acts out a more automated role, while the Filler is clearly the star of the show. Still, I enjoyed both roles equally, though I may be a bit biased.
During the design process, I often relied on a solitaire variant of the game, whereby the sole player would take the role of Filler and would simply shuffle the corpses and zombies and deal out three random cards each round. This mode proved that the zombie player's role could simply be automated without affecting the game's flow.
A large part of the game's pseudo-strategy, however, relies on both players trying to second-guess each other. Rock, paper, scissors is fun, but only when both you and your opponent are over-thinking your decisions. Playing rock, paper, scissors against a computer is pointless, because the result is always random. The same goes for the zombie player's role: It's more a mental game than a strategic one, which is ironic because zombies have never been cast as thinkers.
Still, that's not to say that the zombie role is without its own strategy. In either position, I designed the gameto allow players to keep track of each other's resources. If you're the zombie, you're paying close attention to how many cement cards the Filler's used so far. If you're the Filler, you're watching carefully to see which zombies are left in your opponent's hand. When push comes to shove, I'm very pleased with how the game turned out, even if it is merely filler.
Happy Halloween, and enjoy playing.
Scott Jon Siegel is an enthusiastic game designer, a professional blogger, and a mediocre cook. His words and games can be found at http://numberless.net
"The Filler" illustration by Bonnie Ruberg.