Just like Plants vs. Zombies, you’re tasked with stopping the advances of a zombie horde that moves from the right side of the screen towards the left, and as the game progresses, the action is interrupted with trading card-like introductions of new characters. The 20 characters are predictable in concept—faster ones, slower ones, ones who shouldn’t be hurt—but they’re amusingly executed: cartoony wolfmen, Frankensteins,…