There are two primary ways players encounter these features:
Killing higher-level zombies and destroying tombstones are the most efficient ways to earn gold and XP needed for legitimate weapon upgrades. Zombie Defense – Manual and Guide - Home Net Games ZOMBIE DEFENSE TYCOON INFINITE AMMO A NO SPREAD
Completing your base allows you to "Rebirth," which unlocks advanced base upgrades not accessible during the initial playthrough. Advanced Strategy for Defense There are two primary ways players encounter these