Mad Space is the twelfth stage in the Dark Story of Sonic Adventure 2. It is the final treasure hunting stage exclusive to Rouge the Bat, and the equivalent to Knuckles' stage, Meteor Herd. Her actual boss fight with Knuckles, however, takes place on Meteor Herd. This stage's background music is "34°N, 23°E", with Tabitha Fair as the vocalist.
Rouge sets out to the outer perimeter of the Space Colony ARK to retrieve the rest of the Master Emerald shards and then flee the ARK. She obtains three of the Shards, and is then confronted by Knuckles, whom she then fights. After their fight, Rouge runs at Knuckles in an attack, but slips and falls towards a lava-like substance. Knuckles (claiming he only did this for the Master Emerald), catches Rouge's hand and pulls her up. Rouge then pulls her hand away and gives Knuckles the rest of the Shards, which he then fuses together with his own Shards to reform the Master Emerald. Knuckles then apologizes for hurting Rouge and runs off.
The stage takes place in space where Rouge must collect three shards of the Master Emerald. The stage has three planetoids that may have one of the shards. There are also floating areas in the lower areas of this stage. Like Meteor Herd, the stage also has large containers and some of the space colony's platforms. There are also GUN Hawks in this stage.
Level Up Item
Rouge's Iron Boots Level Up Item is located in this stage on the spherical planet. It allows her to break steel containers.
The hints in Mad Space are much different from those that are in other treasure hunting stages. The first hint is completely backwards being only readable when "onhere arhe tters" backwards. The last two are written regularly, but tell the exact opposite location of where the emerald piece actually is.
The name of the song, 34°N, 23°E, if translated into coordinates, it turns out that the location of 34°N and 23°E is in the Mediterranean Sea, just north of the coast of Libya, Africa. It's unknown if this was an intentional reference or simply a coincidence.