Centipede, Millipede, Missile Command

Centipede:  The fast-moving action includes a variety of creatures dropping down from the top of the screen or flying in from the sides, most of them to attack the player.  The player's shooter is represented by a somewhat humanoid head.

Millipede:  The game action takes place on a playfield filled with mushrooms, flowers, and deadly DDT bombs. The player tries to destroy a variety of insects that drop from the top of the screen or fly in from the sides.  The object of the game is to shoot and destroy as many objects as possible for a high point score.

Missile Command:  This game depicts an Armageddon-Style war in which players defend their bases and cities with Land-to-Air antiballistic missiles (LTA-ABM).  The enemy launches incoming waves of attack missiles.  In addition the enemy occasionally launches missiles from a Fast Mover (A moving satellite or bomber).  They will also deploy Smart Bombs that can sometimes avoid your  LTA-ABM's.

Defender & Defender II

Defender:  The classic side scrolling shooting game.  This fast paced game puts the player in command of The Defender Star Fighter.  The mission is to protect the stranded humanoids from Alien Abductors.

Defender II:  This game was also known as Defender Stargate when it was released in 1981.  Similar to the first Defender, Defender II added a few different levels and more difficulty but the primary game play is the same.  

Joust & Robotron

Joust:  At some far distant time two fantastic gladiators meet and square off for battle.  Each is mounted on a fanciful Ostrich like bird of prey whose wings can carry it from the cliff tops to the mouth of the Abyss and hopefully back.  Fight the Computer, a second player, or both.

Robotron 2084:  In this classic arcade game, a player is placed in the role of a mutant human, who has the ability to shoot a laser from his body in eight different directions.  The player's mission is simple: Save humanity from its own creation - The Robotrons.