JoSyrux

From Juergen Trozki:

16 planets are being attacked by the aliens. The higher the game level, the more merciless their attack becomes. Only your skillful and intelligent defense tactics will prevent them from conquering all of the planets. To do so, you need to figure out the aliens' attack strategy: indiscriminate firing will only lead to you being destroyed. JoSyrux has two game modes: first, game play with the object of freeing a planet and second, game play with the object of reaching a high score.