Anticlimax Boss: Andre. He does nothing at all, and you defeat him with one move. To be fair though, Final!Reflux was doing all the work.
Big-Lipped Alligator Moment: The Bog of Murk. This section has no plot importance, Globox is absent for the majority of the level, Andre has no dialogue, and Rayman fights two villains who aren't connected to the Hoodlums in any fashion.
Idiot Plot: A huge portion of the game could have been easily avoided if the doctors could show up all at once the first time Globox set foot in the clinic.
Scrappy Mechanic: After a while, you'll start getting really annoyed by the fact that Rayman has to somersault EVERY time he jumps, which seems to slow him down.
So Okay, It's Average: While the games humorous tone and critical reception was all around good, the gameplay is rarely considered to be as good as Rayman 2: The Great Escape.
Tough Act to Follow: You won't find anyone who considers this a terrible game, but it carries the curse of being in the shadow of its predecessor. Considering Rayman 2 is one of the most critically acclaimed games of all time, it's really not that surprising, but it's a huge reason that this game doesn't tend to get a whole lot of recognition. There's speculation on this being a huge reason that any actual sequel was put on ice for years until Rayman Origins came along.