The fact that this game spawned such a big franchise is telling of the state of video gaming in 1981. At least most of its sequels were better.

Space Invaders on drugs. Not necessarily better, just more things happening.

Honestly pretty boring. I can't even say the concept has been improved on because all the modern clones I also find boring. Don't bother.

Classic quarter-eater. Decent concept, gets old fast.

It's Pac-Man.

Very cryptic, walkthrough practically a necessity, but a decent evolution of earlier text-based adventure games.

There's better versions of the concept out there today, but it's still a fun time.

It's singleplayer Pong. Simple and fun for a brief period.

Its influence can't be understated, but for today's audience, it's not worth playing.