Humans are drawn toward a flight of stairs that suddenly appear one day, and they start to walk toward a spaceship hidden among the clouds. When there are no humans left on earth, the robots start to talk about taking over the planet.
http://en.tezuka.co.jp/anime/sakuhin/subtitle/ts002.html
Everybody loses interest in everything except climbing the stairs. Atom is freaking out.
The robots go to the rescue.
This alien bird resembles one from The Adventures of Rock (Manga)
Chiko
