Use the left and right keys to move your ship around. Press the up arrow to fire missiles at the enemies. Destroy all 24 enemies to move to the next round. But watch out! The enemies will shoot missiles, too. It starts off easy, but gets progressively harder and faster. The further you progress, the faster you can shoot missiles! Since I have not played Space Invaders in real life, this is probably closer to Galaga.
Press Z to fire a missile(s), press X to launch a bomb, and press C to shoot a laser. You are only allowed one bomb per level, so use it wisely! Heat seeking missiles make the game a lot easy! Think that they take all the fun out of it? Press M to turn them off. Run it on Turbowarp for better quality: https://turbowarp.org/810094897?interpolate