Star Defender Description:

Vertical scrolling space shooter. Advanced clone of Space Invaders. 
You are a test pilot flying the Tornado.
Your ship is controlled by your mouse. The ship is limited to movement in the lower line of the play area.
To fire, press the left mouse button. If you have rockets - press the right mouse button. Tornado can have up to 5 levels of power-ups. Each level gives you both more life and a more powerful weapon. Every time you are hit, you will lose 1 power level. When all power levels are depleted, your game is over.
The different types of enemy ships attack in waves. Each type of ship has different weapons, attack style, and AI. Each level consists of several waves. The last wave of each level is the big boss.