It's funny that you don't really get an impression of what this is all about on the front page. I don't know what a Vectrex is, and I'm confused. Something with games I guess.
Vectrex was an old game console with an integral CRT, famous for the "vector scan" CRT it used.
Basically the only new principle involved is that instead of cathode ray beams always scanning on a fixed rectangular pattern, the X and Y deflection amounts were provided by the game to move around the singular dot to desired locations.
It's crisp as waving around a laser pointer. Some people like that aesthetics.
Yeah, maybe you're expected to be of a certain age or into retro underdog gaming systems? It was upvoted to the front page so…
Yeah, Vectrex was a vector gaming platform (as opposed to bitmap) that came and went in the 80's. Vector arcade games were a kind of niche anyway — like "Asteroids", "Battlezone", "Tempest" and a Star Wars game. But they were also kind of magical. The Vectrex captured that.