Hallofpool

Thanks, VectorGamer. That is it. Not monochromatic, but it has been 35 years...

Trying to remember the game I played in early 80s arcade. It had 4 large round buttons arranged in a diamond shape serving as a d-pad for directions up,down,left,right. It had two large buttons flanking the d-pad for firing the game weapon. The game consisted of defending a central area by firing a cannon outwards from each side of the center. Moving the cannon using the d-pad buttons and firing it with either the left or right fire buttons. Enemies would fire shots to the center or run around the perimeter before attacking the center. When you were all out of lives, the screen would explode and the noise was very loud. Believe it was monochromatic (amber?). Played it before 1986.