Well, since we've got nothing to talk about, I might as well start by going over a brief review of Rayman on the DSi, which I've beaten not too long ago.
Rayman DSi pretty much looks and plays just like the PC version that I have, only with some differences. First off, the difficulty has been curbed a bit, in which Rayman has been given extra hit points to his default health, while grabbing a Max Power doubles it, more or less, making it more easier to last against enemy infested levels. Plus, the number of tings to collect an extra life has been halved to 50, and you don't lose any collected tings whenever you die, making extra lives easier to earn. While the levels themselves are still challenging, the extra health and easy-to-collect extra lives does make it all more forgiving. However, one major drawback is the reduction of the mercy invincibility time, in which each time you get hit, the invincibility lasts for almost a millisecond before you get hit again. It doesn't help that you get knocked back each time you get hit, with little to no time to react before getting hit again instantly, which is problematic if you're trying to get out of a spiked pit.
For the controls, it works pretty well like most versions. One major complaint that I have is that when you get the run ability, it doesn't replace the grimace ability like in most versions. That means whenever you're getting ready to run while standing still and hold down the R button, Rayman does his grimace, leaving him open to attacks or worse. So you have to actually be moving first before running. Another complaint, although minor, is the crawling, required to get through small spaces, done by holding down on the D-Pad, and pressing either left or right, which can be somewhat uncomfortable on the thumb.
In terms of looks, the graphics and visuals are pretty identical to the original ports, to the backgrounds and character sprites. However, due to the game being on a handheld, the game view is significantly cut off for the most part without having to move to scroll the screen, making it harder to view any incoming enemies or obstacles in foresight.
Now for the sound and music, it's fairly identical to the main versions, but with certain drawbacks. For example, the main SFX volume is considerably louder than before, especially when your DSi/3DS volume is already set to max, so it gets hard on the ears after a while. For the music, it's fairly recognizable for those who played the original ports, despite being at a lower quality. However, due to the DSi's software being limited, a number of songs from the original version ended up being cut from this, with the songs in-game being shortened and set on loop.
While not much has been changed in this version, there are some additional features. First off, the game features a level map viewed on the touch screen that you can scroll around for a good look for what's ahead of you. While this seems useful, the black and white style of it seems unappealing to the eyes, and it lacks the feature of showing any Electoon cages that you may have missed, which would've been very helpful to any newcomers of the original Rayman.
Another feature, making use of the DSi/3DS internal camera, is the Photographer Checkpoints, which the game take a picture of yourself while saving your position in-game, with the image being displayed on the touch screen while on file select. It's a fun feature, but the loud camera clicking sound that the system makes gets annoying after a while, even if you're volume is turned all the way down.
One last feature, although it's not truly vital to the game itself, is the Anti-Dark Matters Achievements List, which basically lists the worlds that you've beaten, all of the cages that you've found, and if you managed to clear any worlds without using a continue. Like I said, there's no real reward to clearing the list, aside for bragging rights.
But one handy subtle feature, probably not mentioned anywhere in the game manual, is that whenever you revisit a level that you've already cleared, especially if you're trying to track down any Electoon cages that you might've missed, you can hit the Select button on your system to skip to the next part of the level without having to beat it all over again.
Overall, for my thoughts on Rayman DSi, it's a decent port of the original. Much better than Rayman Advance, but not as good as the original console versions, due to the hardware limitations. It's definitely recommended for those who want to play Rayman on the go, but for those who played the original, you're not missing out much with this.