I completely rewrote the rules of the game, inspired by the 147 variants available here and there, and added some personal changes too. The game's now a much more strategic and complex coop variant for 2 to 4 players (3 might be best) fighting all together against Zombies; some kind of card driven cardgame. Rules are made to play with the main game and all expansions from 2 to 6. It's even better if you possess the "Humans" boardgame from Twilight Inc. as figs might be used as stronger zombies...
The main idea's that event cards targeting opponents are to be immediately revealed and played as unexpected events. Weapons have durability and may be used more than once. The use of Guts tokens's also critical. If one dies, all players die and game's over!
Everything's detailed in the files I recently uploaded (complete rules and a player aid). If you have any question, I'll be glad to answer. Enjoy.
We succeed playing with a single pawn each. But it was tough. In this conditions, you've no other choice to stick together (as you get a +1 bonus to your die roll when you outnumbers zombies on a space) and advance slowly. But it works.
What might be interesting with this variant is that it might be used in a 2vs2 game. Players targeting the opposing team when drawing "bad" events. We didn't try yet but it should work well, I guess.