I had the PS1 version growing up and at the time I had no idea that version was actually lacking content from the other versions of the game. It was a nice bonus that the PS1 version had an exclusive secret level where you got to play one level of the original Rayman 2 beta (back when it was originally still going to be a 2D game like the first one), but now I understand why people regard the PS1 port as the "weakest" version of the game while the N64 and Dreamcast ports are more well regarded (in fact I think it was made for the N64 first).