Infinite Levels: Galaga or Galaxian?

Factual Questions
1

Which is it? I think its Galaxian, but I want confirmation.

2

I know Galaga was the sequel to Galaxian, so I’m pretty sure it’s Galaga.

3

I know I’ve rolled the score on Galaga more than a few times. I don’t know if if can go above 99 levels, though.