You control your ship by using the left and right arrow keys and fire by hitting the space bar. Your goal is to protect your generators from the waves of incoming ships. Between each wave, you are able to purchase upgrades for your ship, shields and generators.
You earn points by killing enemy ships and use these points for purchasing upgrades. The upgrades are:
- Extra life grants one additional life to the player. When you run out of lives, the game ends.
- Increased health boosts the health of your ship, letting you take more damage before dying.
- Increased speed boosts the speed of your ship, letting you move out of the way of incoming fire more easily.
- Fast firing speed boosts the rate of fire of your ship, letting you take down the enemy waves more quickly.
- Weak Turret purchases a single, auto firing turret that sits in front of the generator and fires at enemies. If the generator is destroyed, the the turrets will stop firing. You can have up to 3 turrets on a single generator.
- +100 health restores 100 health to a generator, buying it a reprieve from destruction.
- Increased armor boosts the armor of a generator. Armor reduces the damage from incoming shots.