Although it isn't mentioned on the box or manual, Rayman 3D is yet another port of Rayman 2. As ports go, the visuals are as faithful to the original as they can get. The game is apparently sourced from the Dreamcast version, so if nothing else, Rayman 3D is a great way to show off the 3DS's visual boost. At the same time, most of the problems that plagued Rayman 2 haven't been fixed, leading to the 3D issues.
If the 3D leads to anything meaningful, I hope it leads to better camera systems. The camera is the biggest issue facing the game. It will randomly switch viewpoints or, more commonly, get caught up on level objects. As annoying as these issues normally are, they're a headache in 3D. Though by no means the worst implementation of 3D I've encountered (that honor goes to Madden NFL), I usually dialed the 3D effect down. Even then, I still had issues with the image suddenly blurring or producing an odd visual "shadow." I originally thought the issue was a hardware limitation, but after a few tests concluded it was the 3D effect and camera not getting along.
I've always liked the sound design in Rayman games, not because it's particularly good, but because of how it fits into gameplay. The squeaky cages and diminutive cries of "Help!" are a nice motivator. It's possible to run through the entire game without collecting every Lum, but at the same time, the shouts are enough to make you want to seek them all out.