If you've played Zombies!!! but found it lacking in the strategy department, this expansion will give you what you need. The new event cards are enough by themselves, but with the addition of new map tiles, you can pursue a whole new course in the game. With this and the 3.5 expansion, after editing the deck down (removed about 20 cards), we were able to squeeze more variety into our game. Some of my friends worked towards the military base, attempting to hit the motor pool for the added movement, others chased after the helipad, while I made full use of the new event cards and scored my 25 zombie kills (which is a lot more feasible with the expansion).
The addition of the super zombies is actually very nice, as well; being able to harass your friends with a few fast-moving and hard to kill zombies makes for a new way to annoy your competition.