999999999 cash, no build time.
Your goal in this zombie killing game is to stay alive as last as long as possible.
As the levels progress zombies will become stronger, faster and more numerous. On top of this zombies will start coming from more spawn points. You gain more money for killing zombies at the edge of the map, for example you gain +4 for killing zombies at the edge +2 for kill zombies near the edge +1 for killing zombies near your HQ and nothing for killing zombies around your HQ.