In Contra, the player controls one of two armed military commandos named Bill and Lance, who are sent on a mission to neutralize a terrorist group called the Red Falcon Organization that is planning to take over the Earth.

The main character is equipped with a rifle with an unlimited amount of ammunition. The player can also jump, move and fire in eight directions, as well as move or jump simultaneously while firing. A single hit from any enemy, bullet, or other hazard will instantly kill the player character and discard the current weapon.