Development documents and 68 (!) prototypes for Rayman 3 on GBA have been publicly released on the Internet Archive - eviltoast
Rayman 3 GBA Prototypes : Free Download, Borrow, and Streaming : Internet Archive
archive.org
Here are 68 prototypes of Rayman 3 for the Gameboy Advance. The earliest three builds still refer to the game as Rayman 2, before it was changed over to...