The new features aren't quite as exciting at all
The Legend mode gets pretty bored, there're only a few stages with a limited amount of selectable charactors. And they are all pretty short.
Extreme mode, well....in that they tried to add some RPG elements to the game, but the missions are still boring. Most importantly, when you train up a charactor in Legend mode, all the status won't go into the Extreme mode, the two things are completely seperate.
For the sound, not many changes, background music is Rock as usual, the voice acting, no changes
Graphics, well it's Dynasty Warriors, so there are no changes but the graphics are good
Overall, they really should have kept the Musou mode and Free mode, the Legend mode is a bit forced, although you can use different charactors after completing that stage, but you really wouldn't want to play through it again, the new difficulty can be challenging. If you have the original Dynasty Wariors 5, get this game, so you can enjoy the extra stuffs, if you don't, then don't get this game, the not-so-exciting features are gonna bore you to death.