Skies of Arcadia Demos

Eternal Arcadia Tentou-you Demo Movie
The Eternal Arcadia Tentou-you Demo Movie (エターナル アルカディア 店頭用デモムービー) is a demo disc that contains a demo movie meant to played in Dreamcasts at Japanese stores.

Official Sega Dreamcast Magazine Vol. 9: December 2000
Came with the Official Dreamcast Magazine (US), and has a Skies of Arcadia: Trial Edition.

Dream On
Demo discs from the UK Dreamcast Magazine

DreamOn Volume 19
Has a trailer

DreamOn Volume 20
Has a playable demo