Space Invaders and Asteroids were both landmark classic arcade games. Both were available online here for you to play in your browser at the click of a mouse with no download required and completely free. Unfortunately the provider of the games has had to withdraw Space Invaders.
Space Invaders came first and was a relatively simple game but incredibly addictive. Simple sounds accompanied the march of the invaders and the beat of the player's heart and the rhythmn of successful game-play. The sound of the march speeding up as the invaders' numbers fell and they advanced more and more quickly along with the player's panic levels.
Asteroids represented another level of game complexity and was the first popular game to include a free moving ship that could thrust at frightening speeds and kept its momentum through the vacuum of space until opposite thrust was applied. A huge step forward in game-play requiring the mastery of brand new skills with quick reactions and hand-eye co-ordination.