User blog comment:DevilX90/Stages From The Demo/@comment-24503190-20140730013430

Maybe they just haven't finished programming Ridley as a stage hazard yet. After all, Sakurai only showed the shadow of Ridley just hovering there; he might still be programming his attacks. Also, there are some lava pipes in the background that aren't in the Final Destination version, and since stage hazards aren't in the FD versions, that could mean that there is lava as a stage hazard. That might also be unfinished.