Just played the demo for a few minutes. The game is certainly fun enough to warrant a $10 investment, in my opinion, but presented some problems to cabinet use.
1) Like many games that might otherwise be cabinet-ready (@*&$^ gish), you can't navigate the GUI to start a game with the keyboard in any sort of up/down/left/right/select fashion. You'll need to use the mouse to initiate a game, choose a level, dismissing high score prompts, and so on. and
2) The game itself uses a surprising number of controls. The camera control, as far as I can tell, is fully manual, and can be controlled either with the mouse or via keyboard (or joystick when using a keyboard encoder, of course), so that'll require 4 buttons for camera left/right/up/down. Moving the marble, unfortunately, locked to keyboard (I'd much prefer a marble-madness-style trackball interface) but can be remapped, so that's another 4 buttons for moving the marble up/right/down/left. If that were all of the controls, I think the game would play fine with either a robotron setup, or joystick + 4 buttons. However, there's also the matter of the "jump" button, and "use powerup", so that'll require a few more. The game, then, can be played with a street fighter setup, or top-fire robotron, but it feels somewhat uncomfortable to be constantly changing the camera angle with one hand, while trying to actually play with the other. That may just require some getting used to, but I still think a 3rd person camera locked to the marble's movement would be quite welcome.