If you realize a wave is too fast for your current setup, sell non-essential towers to instantly fund a high-damage "Splash" tower or a "Freeze" tower.

In modern emulators, use Save States before a difficult wave. If your maze fails, reload and adjust one single block. This allows you to "brute force" the perfect pathing solution.

Leave a small gap near the exit. When the enemies are almost there, place a tower to block that gap and open a new one back at the start. The AI will turn around and walk the entire length of the map again.

The highest quality "cheat" is the . Build a long corridor with an opening at the end. When the boss is halfway through, sell a tower at the entrance and block the exit. The boss will be forced to walk back the way they came, effectively doubling your damage window without needing more towers.

This is the most broken combo in the game. Use Freeze Turrets to bunch enemies together, then use Sonic or Plasma towers to deal massive Area of Effect (AoE) damage to the entire group.

Use the cheapest towers (usually Turret Level 1) to define your path. Do not upgrade them until your maze is complete.