Overview
The Falling Men (砂飛行, Sand Flight) are tiny stick figure decorative characters that appear randomly in the backgound of the Stairway to the Sky in their own event. They appear as the player walks up the steps towards the top.
Appearance
The Falling Men are simply drawn stick figures that spiral around in the sky (like the UFOs and Severed Heads), although they never reach the ground themselves. When the player walks across two tiles along the stairs, a 1/4 chance is triggered for each one, although the second one can only show up if the first one did, making the second one rare to encounter.
Their in-game sprite.
Speculation
A few fans have pointed out and speculated that these characters could be foreshadowing another important event in the game.