QIX

One of those games quickly achieving cult status that you both hate (for being too damn hard to play in an arcade full of people yelling around you) and love (because it breaks new grounds).
You're a drawing marker (though I like to think of it more in terms of a futuristic vehicle as seen from way, way up) marking area by area of a rectangle screen with the aim of claiming  at least 60 percent of the rectangle, all the while avoiding direct contact with the Sparx who thread the same paths you did and claiming an area without it being touched by a mysterous entity the game was named after.

It's a fun and exciting play, so I guess its quick decline in popularity has to do with somewhat abstract graphics that didn't clearly indicate what you were seeing on the screen. Being a game ma(r)ker has always been hard. To me this is as essential in the history of gaming as Tetris, Pang, Block Out and other like-minded games. Try it for yourselves on any of the browsing game sites with classics nd you'll see how great it is.