Ambush is a space shooter which is played on a single screen with no scrolling. You can move your vessel all over the screen, shooting at enemies or avoiding collision with them. Enemies enter the screen from the top and move at various directions and speeds toward the bottom (they bounce and change direction when hitting the left or right side of the screen). When hitting one of them they split into smaller ones, which may have a changed direction and movement speed (this is repeated for the first and sometimes for the second hit). The sprites created from a first hit will not leave the playing field but rather bounce from the bottom edge, but the smallest, created from a second hit, will vanish once they reached the bottom. Those sprites which weren't hit at all will re-enter the screen from the top. The overall number incoming enemies increases over time (as soon as one wave was completely destroyed). The game has some basic sound effects (laser and impact sounds), but no music.