go on experimental mode, buy every perk and every weapon, and every health pack. then when out in the parking lot, press P and go to "zombie spawn options" then put up to 30x and enable every zombie. makes for EPIC GAMEPLAY. its all i do now :)
better on iPhone/iPod touch where you have to discover 196 elements and 21 groups. finished it yesterday, now just trying to remember all the basic element combos. :D
 "Endless Zombie Rampage 2"){kind=icon}
 "Doodle God"){kind=icon}
 "Final Ninja"){kind=icon}
 "Thing-Thing Arena 3"){kind=icon}