Did Batman and Return of the Joker start out as something other than Batman games? Probably doesn't apply to the first, but this really seems to be the case with the latter. It has absolutely nothing to do with the franchise except having bits of art in between gameplay with Batman and the Joker as stand-ins for the original sprites. Batman has uncharacteristic energy guns and powers up in an electric blaze to fight bosses. The Joker is always midair inside a mechanical pod like Dr. Eggman. The final boss looks more like a contraption out of Contra.
Batman at least has locations that look like Gotham City and apparently a bunch of enemies from the actual comics.
Batman at least has locations that look like Gotham City and apparently a bunch of enemies from the actual comics.