I remember playing the demo of Jade Cocoon off a PS1 (PAL) demo disc with a friend when that was new. We were both 100% convinced it was the Pokémon killer. Why would you play Pokémon Blue or Red if you could have Jade Cocoon in 3D? I didn't even realise it had pre-rendered backgrounds at the time. Pre-rendered 2D stuff is the worst for making you feel like an idiot when you look at the games you thought looked fantastic at the time.
Edit: Should be on US disc 21, if the CDs have the same numbering as the magazines. I think we used to get UK demo discs over here, so it would have been UK demo disc 53.
I remember that, being a kid that was really into Pokemon having a 3d style Pokemon game come out was amazing....don't think I ever got the game though which was weird considering I still remember it to this day.