Darius pointed me here. Eee!
In case I haven't been entirely clear, I love - absolutely adore - 2D vector games. Examples of 2D vector games are fighting games and scrolling shooters (shmups). Even 3D fighting games are actually 2D vector games. Platformers such as Metroid are also 2D vector games, although not the style I prefer.
But before them all came Pinball.
Back when I was just a wee boy with my Apple II, I did two things: I wrote my own games, and I played two games. At least, two games I can remember. One of them was Hard Hat Mack, which I remember only because it was the first game I ever misplaced, and I spent a few hours every week searching for it in vain.
The other game was the best game ever (at the time): The Pinball Construction Set. With a picture of a white hand holding a silver ball over a Tron grid. Although, at the time, I didn't know Tron.
I don't think it's stretching to say I "played" that "game" for hundreds of hours, in one-hour increments. (More than one hour and the Apple II overheated, randomly flipping bits.)
It was the beginning of my love for vector games, and it has never been fully replaced by anything else. It was also a very solid place to begin, since it taught the simple fundamentals that all vector games are built on.
I never built my own pinball game for three reasons. First, it's really tough to get the physics simulation to work believably. Second, it was beyond my programming skills when I was young and beneath them when I was older. Third, I had the Pinball Construction Set, so I built dozens of pinball games inside that. You know what I found?
It's really hard to create a perfect game of Pinball.
After all, the relationships between bumpers, sinks, chutes, flippers... all so complex! Even the basic Windows pinball program, "Space Cadet", is dauntingly complex, with all the flashing and bouncing.
Most vector games are deceptively simplistic. Some rely mostly on speed, some rely mostly on tactics, but they all have one motion. They don't bounce. Bouncing makes vectors really hard to track.
That's why Pinball has only one ball - two, if you're playing hard. I even once played a (real) pinball machine which put three silver balls in play. That was a rush, but insanely difficult. After all, that's three balls which are constantly changing direction. You can't just glance at them, say "it's heading there", and look away. They'll be bouncing off something soon. In fact, in that particular game they ended up bouncing off each other, which totally screwed up my mental game.
Seeing the Gamasutra article brought it all rushing back. Recently, I've been analyzing different vector games, coming up with the math to balance and dissect them. I long ago applied them to shmups, I'm researching applying them to fighting games. I'll make sure to add pinball to my list.