You start inside a spaceship where the only thing you have to do is sit down in the control chair and start travelling at hyper speed.
Then you receive a message from H.Q. They found the enemy base. You have to enter it and destroy the mainframe computer that controls all the robots.
You have to control the spaceship, avoid the base walls, and fight with the robot squids. They'll fire at you, but you can parry with an energy shield.
You rotate the ship with the WASD keys or arrow keys, fire with space and raise the shield with the 'S' or 'DOWN' arrow key.
The game is quite similar to the Asteroids and River Raid. You won't lose your progress because of a checkpoint system.