A secret underground race on an island in the Atlantic ocean has stolen top military vehicles and equipment from around the world and have rebuilt powerful war machines from them. They are even piloted by robots with one mission: to destroy. Military and intelligence officials of major countries have detected them, but they are afraid that they will be unable to prepare against an assault by this underground race. Their plan is to send you in to infiltrate their base and destroy them before they have a chance to unleash the war upon the rest of the world.

You can choose to control either the Helicopter or the Jeep, which have different advantages—for instance, the Helicopter is not stopped by obstacles but the Jeep can fire in any direction. There are nine weapons (five permanent, four short-lasting specials) you can pick up along the way to help you destroy the enemy.

• The music used for boss battles and the entire final level of the SNES version is lifted from a scene in the film The Terminator where Kyle Reese and a female fellow Tech-Com soldier engage an HK tank.

• Silkworm, the original game in the series.
• SWIV, a very similar game on various home computer platforms