Well, it is a DS game, at it's best the DS can feature graphics somewhat better then a PSX.
I'm trying to learn some Megadeth songs, but damn. They are either highly techincal and and hard, or their all over the place and wicked fast. At least Mustaine's solos are easy to replicate, pretty much moving both hands as fast as you can on the pentatonic box, not necessarily in sync with each other.