On Air Man's Stage, if you enter the boss room and use Item-1 to climb back up and touch the boss door again. Mega Man will be moved to the right past the boss room into a version of Wily Stage 2 which loads sprites from Air Man's Stage rather than its own. Enemies from Wily Stage 2 appear in their respective spots and the stage is fully playable up until the boss room, which is an empty blue void that the player can't progress past.