World of Trophies
From the Super Mario Wiki
The World of Trophies (referred to as "This World" in Smash Bros. DOJO!! and on trophy descriptions) is the general setting of The Subspace Emissary mode of Super Smash Bros. Brawl. The characters that appear in the world are described as being trophies that do nothing but fighting. After a character is defeated, they revert back to a trophy. The stages in the world are made up of a large stadium, a forest, a large grassy land, a jungle, mountains, a large lake, a deserted zoo, King Dedede's Castle, a swamp, a desert (which also includes a large castle), glacial mountain, some ruins and a large floating island with a secret base.
Many years ago, the Ancient Minister and all of the other R.O.B.s lived on the floating Isle of Ancients. However, Tabuu invaded the island and all the other robots were taken hostage on his orders. He converted the island into a Subspace Bomb Factory and told the R.O.B.s to get to work on making them, except for the Ancient Minister, who was told to go around and place Subspace Bombs on various parts of the World of Trophies, drawing them into Subspace.