Okay, I've seen other people on this forum posting that nothing is missing from this version of Rayman 2, but I've noticed there IS something missing.

It's at the start of phase 2 in The Cave of Bad Dreams (this is the phase where you slide down a slippery slope with crystals on it, while being chased by Jano).

You start this phase at the top of that slope. When you walk past the skulls on the path for the first time, there's supposed to be a short cutscene. In that cutscene you see Jano coming out of the ground, behind Rayman's back. Jano then says 'Your trip ends here!'. Rayman looks back and is scared when he sees Jano, who is about to devour him. After that, Rayman goes down the slope (and Jano goes after him).

If you die on the slope, you start at the beginning of this phase again, but the cutscene won't play a second time. Strangely, in the GOG version of the game, the cutscene doesn't play at all. I think this should get fixed somehow (if that's even possible) - maybe there's a missing file in this version?

Actually you are wrong...I jest played the Cave of Bad Dreams and that cutscene is there...it only plays the first time you enter and not every time you die and respawn...so ya...

That's strange. I'll play the level again on a new savegame to see if it's there now.

That scene worked for me to when I played it.