Gun-Brick is a orange square with a white rectangle coming out of Gun-Brick. Gun-Brick has a white deflector shield on one of its sides. A light blue rectangle is below the white deflector shield and a dark blue rectangle is placed on either side of it. The rest of Gun-Brick is light brown, dark blue, white, dark yellow, and light blue.
Gun-Brick can be moved left or right by the player pressing the left or right arrow keys. It can shoot with the up or down arrow key or the space bar. However, shooting will propel Gun-Brick the opposite way the gun is facing. So in order to move to higher platforms, Gun-Brick's gun must be facing down, and firing will propel him the opposite way, which is up.
A white deflector shield is on Gun-Brick's back, which will deflect all bullets back in the direction they came. Gun-Brick can also fall down with the shield side downward, which will crush any enemies below it hits. If Gun-Brick touches a enemy, enemy attack, or hazard Gun-Brick will explode and respawn at the last blue respawn block that Gun-Brick touched.