The main objective is to defend your base from waves of alien attacks. You achieve this by strategically placing towers along the designated paths to stop enemies before they reach your base.

You earn resources by defeating enemies and completing waves. Each enemy you defeat drops a specific amount of currency, which you can use to build new towers or upgrade existing ones.

Yes, you can pause the game at any time during a level. Simply tap the pause button, which is usually located at the top corner of the screen, to take a break or review your strategy.

To upgrade your towers effectively: 1. Identify your strongest towers based on their performance. 2. Save enough resources, ensuring you have a strategy for upcoming waves. 3. Upgrade each tower at least once for improved damage and range. 4. Monitor enemy types and adjust your upgrades accordingly.

Use a combination of tower types to exploit enemy weaknesses. Place slow or stun towers near the start of the path and high-damage towers further along. Upgrade towers based on the wave of enemies you face, and ensure a mixed defense to prevent being overwhelmed.