It defines cheap. $9.95 regular, now on clearance* for $4.50; The "Gamemon ft2e92", a little USB mini-controller (3x2!)
that's HID-compliant. I got one for explicit game hacking; small, the front 4 buttons can be tapped easily, trickier for the rest, depending on if you want to retain the controller's original buttons for the kid-sized among you. or, remove the case and put it _in_
a device.. it's tiny! cheapo retracting USB cable, though. not much to that bit.
x y axis and 8 buttons total. 12 possible taps not counting the turbo/clear buttons which are specific to the controller.
Worked right away on my MacMame, which is no small feat.
*at least my store had it on clearance. Yours may differ.