SOmeone had a quick tutorial about to how trim up the bezel art so it is just the sides, for vertical games. I think there is a archive somewhere that has all of these modified bezels
This works great cuz youve still got some artwork, but it's designed to keep the playing screen at its intended size. Vertical games the playscreen goes from top to bottom, and theres maybe ~100 pixels on each side that can be used.
The yellow rectangle is the size of the full screen on the monitor. Millipede showed up good cuz of the blue screen, thats the full size of the vertical games resolution