Best bet is to avoid this game and better off replaying Rayman 2 again if you own it.
Gameplay: If you've played racing games before, you don't drive in cars or any other motor vechiles, you'll be running just like you'd would be doing if you were in school stuck doing PE/Gym. Like in other racing games this is more of a on-foot racing game through certain areas from the Rayman series but mainly areas that were in Rayman 2. You'll only playing against 1 runner instead of 6-8 racers at once unlike most racing and party games.
But most of the areas in Rayman rush are poorly rendered and badly detailed, most of the levels are too simple for any Rayman fan or gamer. Can attack other players by throwing lums at the other racer where they'll be stunned for a short time. You can also swing across if you see any Pink floating Lums around which can lead you to certain short cuts or get in front of the other player. There are speed floors which can give you a boost just like you would see in other games such as Crash Team Racing and Mario Kart.
You can play as your favourite charcters from the Rayman series including Glowbox, Razorbeard, and the Robot Pirates.
Graphics and Sound: There isn't much to talk about on the graphics department, comparing the graphics from Rayman 2, Rayman Rush has just been completly rushed not putting anymore detail through out the game. If you've played Rayman Arena or Rayman M (Which is the Europe name for Arena) you'll not be specting much from the PS2 version. Rayman Rush lacks alot of gameplay features and multiplayer as well.
There isn't much to talk about on music but there much to hear most it is all repetative and recycled over and over again. You've still got the same voicing and sound from most of the Rayman charcters in the series, including Rayman puffing for air while running.
Overall: Rayman 2 was one of the best games in the series but fans of the series will be really ripped off with this awful spin title. There's only 5 game modes for Rayman Rush including Time Trail, Target Mode, Championship Mode, Lums Mode and Training but you can easily get all of the modes done under a day. Your best bet is to avoid this game and better off playing the first game or replaying Rayman 2 again if you own the first two games.