Space Fortress (1981)

Space Fortress lets you control a mid-screen base while defending it from enemies emerging from each of the four edges of the screen.

Storyline

You command a lonely outpost far away in the galaxy. The alert sounds. You're being attacked by alien ships from all directions. You destroy some – but they keep coming faster and faster. You'll find Space Fortress positively addicting. It always keeps your interest because of the increasing speed of the enemy assault from all sides. Up to 4 players.