|Saurian lizard men have overrun all twenty-two planets that form the New Earth Solar System colonies, capturing and mutating the resident human colonies into reptiles to use as slave labour at their stronghold base, the Saurian Mega-Star Apocalypse|
In the 3rd game in Midway's seminal "Defender" series, Strikeforce again has the player flying a spaceship over the surface of a series of two-way, horizontally scrolling planets, destroying enemy waves and rescuing humans from the alien invaders; with rescued humans hanging from the underside of the player's ship. Once these tasks have been completed, the mothership arrives to pick up the player's ship, together with any humans they have rescued. Players can decide which planets to attack, when to purchase additional firepower and when to attack the Apocalypse.
Strikeforce's graphics differ from the minimalist, stylish appearance of the first two games in the series; with full colour sprites, multi-layer scrolling and colourful, visceral explosions giving the game its own distinctive look and feel.
Game description from www.arcade-history.com