>> PLAY FOR FREE HERE <<
Space Invaders is one of the all time classic video games and kickstarted the modern games industry. It introduced the world to... fighting aliens! There wasn't much before it, Pong and Breakout basically. You can play a fan-created tribute here.
Use the arrow keys to move left and right, use the space bar to shoot. As the aliens get closer, they get faster. Hide behind the shields if needed, and get bonus points and lives by hitting the red invader which flies across the top of the screen occasionally.