Earth lies in ruins after an invasion by an alien race known as the Oblivion. The player, Codename: Havoc, is mankind's last line of defense, with just a single space ship. Codename: Havoc
is a top-down vertically-scrolling shooter with classic gameplay elements. With only 3 lives, the player commands a small space ship against hordes of enemies, in the air but also on the ground. The ship can be hit multiple times before it's destroyed and by shooting complete waves of enemies, weapon power-ups such as lasers and fireballs become available.