Sonic Rush is one of the fastest Sonic games ever...
The graphics are fairly bright and colourful and able to depict the game environment to the extent we expect from a handheld Sonic game. However Sonic (or Blaze) as well as all the boss stages are done in 3D but not incredibly well. The 3D graphics appear quite blocky and even if we don't expect them to be incredibly detailed (after all Sonic is cartoon) I found this spoilt things slightly. Luckily when your running along normal areas of the stages you will not notice this problem too much.
Each normal world consists of two high speed platform stages and then a boss battle against one of Dr. Eggman's (or Eggman Nega's) giant machines. Unlike in Sonic Advance 3 (its handheld predecessor) you don't need to get up to speed, start running and your straight up to high speed. I also found the emerald stages much funner and fairer in this game (although I never did get that last emerald to be truthful) as you use the stylus to guide Sonic along, to attack robots and to obtain rings from the balloons and although these stages are trickier than normal stages they are not impossible to get to and complete. This game also includes a "Rush Meter" at the side of the screen, fill it up by doing cool tricks in the air, defeating enemies, collecting rings etc. When you decide to use the power built up in the Rush Meter you will blast along immediately at top speed destroying all enemies in your path.
Unfortunately this game doesn't have the quality of music the other Sonic games have, this music seems stranger and not really built around any real music genre but you may find a couple of good BGMs in the game you like. There isn't much to mention sound effects wise, same old Sonic.
The plot basically runs along the line that an Eggman from another dimension (Eggman Nega) rips through to Sonic's dimension and the dimension starts to fall apart, a hero-like character from the other dimension (Blaze the Cat) also bursts through looking for the Sol Emeralds in Doctor Eggman's possession. This new character to Sonic is interesting, first displaying a cold attitude much like Shadows although maybe Blaze talks a little more, I won't say anymore than that but Blaze shall return for more Sonic games. If you like Sonic and have a DS this game is definitely one to get and no matter if your not it is most likely worth a play if just to feel the quick-action gameplay.