Sanxion is a side-scrolling shoot 'em up, the goal to traverse each level from left to right avoiding or destroying any enemies and obstacles. The side-scroller speed is controllable, increasing the closer the player is to the center of the screen. The screen is divided in two sections, the upper one with a cenital view, and the lower one, taking up two-thirds of the screen, shows a typical side view. Enemies can come from both sides of the screen in close formations that the player must avoid colliding with.
