Help with a Zombie Card Game

You could have separate HP board and ZP board, keeps track of improvements, weapons, abilities, etc. similar to the World of Warcraft board game.

To add strategy, i'm thinking of little chits moving about a grid board, filled with buildings and such to give hiding places and line of sight.

That's an awesome idea. Reminds of Chaotic, where the cards are strategically placed on a game board, and you can equip your guys with battlegear, and you randomly select a location to battle on.

Separate Zombie and Human decks are probably a good start.

And I would consider having each side play, kinda like a different game but that affects the other player's actions etc. I would also give serious thought to how each player's goals could be different.

Consider something like this: The human player plays a game kind of like Magic.. You gather survivors 'creatures' you equip them with items and weapons 'permanents', maybe you manage certain resources, like ammo, gas, food or something. The human goal could be to fulfill a list of tasks like, leave the mall, kind the truck, lower the bridge etc. to win.

On the other hand, the zombie player could be playing ah... I dunno, but something different ^_^

Another idea that just came to me (sorry, I tend to write these posts over several minutes between work) would be something a little like the old Star Trek TNG CCG where there are locations set up in a line between the two players, each player playing their cards on their own side of the location cards. Another aspect of the ST ccg that I think would fit well with your theme is how players were trying to complete missions in order to win, and missions would entail moving between locations. You could have the human player on his side trying to complete objectives and the zombie player on the other side trying to prevent completion and even invalidate objectives.