After one session with Zombies!!! I had to make changes to just make the game playable.
Modifications to the original game:
1) Each player gets 3 life, 15 bullets and no cards (we dont use them).
2) When shooting at zombies you must roll 4-6 to kill it in the same space. If you are shooting at a distance add 1 to the difficulty to hit for every space away from you. Ex, shooting at a zombie at 4 spaces(squares) distance means you have to roll 8 or more with the d6. If you roll under this you can choose to 1. add bullets to reach the difficulty and continue shooting or you can 2. ignore the roll - then you must end your turn even if you have unspent movement points.
3) Z-3 L-1 B-2 (ex, gas station), The only thing changed is that you now roll 2d6 for number of found bullets at a place (B-X, X=nd6).
Use all other rules as stated in the rulebook.
This makes the game last for 45 min instead of 2 hours...