Up to 4 Zigges, 8 Znaches and 8 Zrocos will spawn at the beginning. When they are defeated, no other enemies will spawn until you hit their base. When the enemy base reaches 99%, a weakened Zigge will spawn, followed by a Bore and more Zigges. Another bore will spawn after 87s.
Use Crazy Hearts for additional cash, and because it's decent against Bores. On the bottom row, iCat, Jiangshi, Heavyweight, Vaulter, and an anti-zombie uber (EVA 1 is good).
Upgrade bank to 9000, and use the anti-zombies to clear the initial wave, then spam everything except Manic Lion.