In the year A.D. 2008, aliens invade the Earth and obtain the support of a quisling human government. Fighter pilots Mark MacKenzie and Jane Sinclair are assigned to repel the invasion with Earth's ultimate weapon, the "Strike Gunner" aerospace fighter. The game's first five stages take place on Earth, and pit the Strike Gunners against typical human technology, such as tanks and fighter jets. The final three stages are set beyond Earth orbit and see combat against the actual aliens, culminating in an assault on their enormous mothership orbiting beyond the Moon.

In the year A.D. 2008, aliens invade the Earth and obtain the support of a quisling human government. Fighter pilots Mark MacKenzie and Jane Sinclair are assigned to repel the invasion with Earth's ultimate weapon, the "Strike Gunner" aerospace fighter. The game's first five stages take place on Earth, and pit the Strike Gunners against typical human technology, such as tanks and fighter jets. The final three stages are set beyond Earth orbit and see combat against the actual aliens, culminating in an assault on their enormous mothership orbiting beyond the Moon.