Backup your files and saves before doing any of this!
1. Rename "XEEN.CC" to something else and start the game.
Note: You should be able to play a "Darkside only" game without issue. You can even put XEEN.CC back and restart the game to "convert" your save to World, keeping your party.
*You need the original Clouds EXE and DAT files (the EXE can be renamed for convenience)
1. Rename "XEEN.DAT" to something else.
2. Get a copy of the original Clouds EXE and DAT files.
3. Start the game using the original EXE.
Note: I have only gone to the title screen and not tried to actually play a "Clouds only" game. It might work, it might not. http://games.playazlounge.net/xeen/CloudsOnly/xeen.dat http://games.playazlounge.net/xeen/CloudsOnly/clouds.exe