1. Open the game in your mobile browser and wait for the screen to load fully.

2. The game screen shows your ship at the bottom and rows of alien invaders moving side to side above.

3. Tap anywhere on the screen to fire a laser shot straight up from your ship.

4. Each tap fires one shot, so tap quickly to shoot multiple times in a row.

5. To move your ship left or right, drag your finger across the bottom half of the screen.

6. Your ship follows your finger as you slide it left and right along the bottom edge.

7. Aim your shots to hit the aliens before they reach the bottom of the screen.

8. When you destroy all aliens in a wave, a new wave appears that moves faster.

9. Watch for special alien ships that fly across the top of the screen for bonus points.

10. If an alien or its laser hits your ship, you lose a life and must restart the wave.

11. The game ends when all your lives are gone or the aliens reach the bottom of the screen.

12. Try to survive as long as possible and beat your high score by tapping and sliding smoothly.