I had a great time with Rayman M...except on the Battle parts. I beat the c**p out of EVERYONE with the Teensies, but I can't even complete the first tier of races, while I completed every battle
The game can get really addictive at short duration, after that it cools down rather fast. Alone, RM is not bad, but multiplayer owns. Ever since I first switched the PS2 on, with RM in it, there had been dozens of HUGE battles between the unbeated Teensies, and the always losing Hunchman800 (my brother XD ).
The music is another plus, though nearly all levels have a recurring theme, it's still quite nice. Ray's and 800's theme are kickass.
My favourite Battle arena is definitely Ly's Palace. For one, it has the fairy on it, even though it's just a huge statue (it would have been nice to have her as a playable character...and maybe Clark XD ), and I always managed to get quite a few swares out of my brother when I use Ly for cover.
Overall, a pretty good game, but best when played together with someone. If you do it that way, it gets addictive at lightspeed! XD