Who created the arcade game "Space Invaders"?

With Space Invaders, he unintentionally invented the concept of difficulty. The game couldn't really process the aliens properly so it was very slow, as you killed them it freed up processing power allowing the game the run smoother causing the aliens to move faster.

I can remember playing this on my Atari.

purely a guess, and the right one too!

the first video game I played alas so long ago !