Vectrex in a Browser
twitchasylum.com
twitchasylum.com
The graphics were pretty different to anything I'd seen before, being vector based, but it was a nice device because it meant I didn't need to hog the family TV.
Their approach for improving the graphics, by providing colour via a transparent overlay was inspired, and lots of fun. My overriding memories of the device are the long-thin controller, which used to be clipped beneath the screen when not in use, tethered by a curly-cable, and the overlay system.
I had an intellivision growing up but the vertex always was interesting because I saw one in a store and the graphics were so clean. (Consoles of the last century had very very blocky graphics)
https://en.m.wikipedia.org/wiki/Vectrex
Vector displays always fascinated me (drawing the screen by moving around rather than scanning each line)
Just a heads up, I nearly had a heart attack loading your page. That sound you auto-play is out of control loud.