List of Mario Party 7 pre-release and unused content
From the Super Mario Wiki
This is a list of pre-release and unused content from Mario Party 7.
The pre-release title screen features Mario riding on the MSS Sea Star, passing by various characters from Mario Party games standing on islands. In the final game, the characters are seen running around the world.
The HUD for certain minigames, such as Target Tag, is different than the final version.
The design of the eight-player Player Panels is different from the final version; it was originally borrowed from Mario Party 6.
Originally, dizzy characters would have winged stars floating around their heads, like in the previous three Mario Party games. In the final version, it was changed to non-descript flashes in front of their eyes.
There seems to exist an unused minigame in the files of the PAL version. In this minigame, the player must use the microphone to wind-up a mechanical Cheep Cheep and swim down while avoiding the mines.