BAD CYBORG ASMEURER, you can try GooBall. It's a much less stressful game, since you can slime and stick to the surface, that way you don't go "out of bounds" when the spacebar key fails to respond in time. (And trust me, it happens way too frequently in this game to make it fun.) And at least GooBall allows you to select all the resolutions supported by iMac G5. And better, it's eyecandy heaven. Show it off to your Intel Mac friends, they can't run it! Hah! It's not UniBin.
(Version 1.3.1)