Sonic Colors (U) ROM

It's a very good Sonic game, the quick-fire nature means it's perfect for its hand-held platform, and if you're only going to pick up one Sonic for your DS, Sonic Colors is definitely your best bet.

This is one of the best Sonic's game on the DS. I really like the 3D effects, there is a really good trancisition from 2d to 3d. 

An extraordinary amusement park has been seen orbiting around the home planet of Sonic the Hedgehog, and rumors are spreading that an alien race of Wisps, who have a unique colorful energy, are being held captive there by the evil Dr. Eggman. Soon after arriving at the amusement park, Sonic discovers he is able to use these mysterious alien forces to help the Wisps escape!

Sonic is back!
Sonic colors marks a new era for sonic...on the wii at least. I was slightly dissappointed to discover that this game is a side scroller a la sonic rush, I was hoping for a true, portable 3d sonic game. oh well.
Having said that, Sonic colors ds is an extremely good game that has a real sense of speed whilst still packing lots of great features, such as wisps. Wisps allow sonic to use different powers (Become a laser, a drill etc).
The graphics are...meh. 3d like nsmb but it's all a bit rough around the edges.
Some of the music is depressing. seriously depressing. 
Sonic colors ds is worth your time if you're a big sonic fan, and is worth a look if you like platformers in general.

The diabolical Dr. Eggman has hatched another plan for world domination! Set in his amazing interstellar amusement park, he is harnessing the colorful energy of an alien race called Wisps to fuel his sinister plot. Sonic will need all his speed and skill as he faces this test, but, empowered by new Color Powers, it's a test he'll pass with flying colors!