Space Invaders is a game where you destroy primitive aliens, you eliminate them as thay descend.
Press start and use the mouse to fire the laser in the combat zone. Anyone over 25 will know this game.

Alien Basic 10 points After 300 points, Alien Rapide starts
Alien Rapide 50 points After 400 points, Alien Mobile starts
Alien Mobile 80 points After 500 points, Alien Paralyser starts
Alien Paralyser 100 points After 1000 points, Guardian Angel starts
Guardian Angel 0 points