Rainbow
>Island, Puyo Puyo 2, Alice in Wonderdream, Jigoku Meguri (Tour of Hell),
>Mizubaku Dai Bouken (Liquid Kids) and Toilet Kids.
Those are relatively rare games, but there are much rarer ones on the
PC-Engine. W/ the exception of Puyo Puyo 2 (and Rainbow Islands to a
slight extent) those games are moderately rare. There are definitely
much rare. The hardest game for me to find was The TV Show -- can't
think of the second hardest. :)
Paul