Fire hawks is literally a Phoenix game but practically speaking it's an Invader mutation. Your mission is to defend your planet from the deadly fire hawks of the title. They come in search of energy and if one lands it turns into a Phoenix and the game ends.
The birds all line up at the top of the screen and you fire up at them with your laser. In the way are Plasma Screens' forming barriers. The birds cannot descend until the screens are removed by your shooting, although there is usually a gap or two for them to use, and you can ' t get at them until you do shoot some holes in the screen.