Starblazer is a space-themed fixed screen shooter, where the player controls a starship: the titular "Starblazer", with an objective to clear each platoon of aliens per round. Players use a 2-way joystick to move the Starblazer around from left to right, and a button to fire the laser. Due to technical limitations, the Starblazer can only fire one laser shot at a time, and must wait for the current shot to hit the top of the screen before being able to fire another.
Enemies come in the form of "Usurpers", as they are known in the North American arcade flyer: alien ships of various colors that appear in formations towards the top of the screen, alongside two escort ships, labeled the "Queen Usurpers". Usurpers will sometimes move around and fly all over the screen while shooting projectiles. The less Usurpers there are on-screen, the faster they move around.
The thing that sets Starblazer apart from its competitors at the time is its unique formations: as opposed to simply using the same enemy pattern, the game cycles through 5 unique formations of enemies each round, adding a layer of challenge and giving way for different strategies. The game features scrolling, albeit limited to the starfield background, while the gameplay remains fixed.
