These are the beta elements of Mario Dodgeball Rush.
The game's original name was going to be Mario Dodgeball Grand Tour when it was still in development. But, by causing a few problems of this title, Grand Tour was replaced by Rush. Grand Tour is shortly in an another game. The details of this game was a little lighter and sharper then now. Sonic was going to be a playable character, but was dropped for Unten(explications = section 3). Luigi Park was once called Boo's Target Court. In this court, the ghosts were different then usual.
When all of the files are extracted from this game, a stage called "mario_stadium_1mdgt" is found. It is just like Mario Stadium with grassfield like Mario Baseball Series, the first stage in the Mushroom Cup, but the difference is that there are no supporters, The sky was just blue without clouds. There is also another course called "draw_demo". It is supposed to look like Yoshi Fruit Court, but the pointers which are supposed to signify where to look in the file for the textures miss slightly, resulting in a graphical mess-up. There was no trees. This unused data is blocked for important reasons.
Sonic was going to be playable, but this character is replaced by Unten, because it causes problems for the game like a bad gameplay and bad graphics. It causes a mess-up for the texture too. Red Paragoomba was going to be playable too to be a tricky character but it's necessarly replaced by Koopa Troopa as defensive character.