The real shooter
The game moved much faster than its peers. Space Invaders didn't offer that additional axis of movement. Centipede let you move forward and backward while dodging. Such a small thing now but it was a huge advantage back then. I was able to dance with the enemy and then end it at my speed.
The gameplay was true fun for a kid with extra energy to burn. The adrenaline was always pumping and the bad guys died by the tens.
I would certainly recommend buying this game and playing it again and again. It is a timeless pleasure that is so rewarding in its simplicity.