It's probably just alternates exits. Did you:
-leap off the walkway with the blue sky that later turns to a sunset (2'?), landing on a small ledge where the boatman takes you back towards the beginning while you dodge fishmen?
-uncover the giant bomb in a wall, ignite it and follow the new path through to the end?
-just after the imp-like guy tries to swipe your item, there is a scale that you need to stand on and knock a boulder loose to fling you up to a hidden exit.
-I think it's the same stage where Medusa heads can knock you down around spinning platforms into an alternate route.
-I think it's stage 5' that has two main routes, one leads downstairs and the other either up or straight.
-I don't know if the game counts the multiple routes to the same exit, but the stage with the red skeletons(?) there is a trigger for one shortcut and another optional area with slow rolling boulders/balls and a pulley with a big buy tossing the balls.