DDR returns with more music, different graphics and harder difficulty.
+ A great variety of songs
+ New battle mode is a nice distraction
+ Better online play
Bad:
- Definitely not for DDR newbies
- Stellar Master mode wasn't as intriguing as Dance Master mode
- Exclusive songs online
There is a great variety of songs with great licensed songs such as Battle Without Honor or Humanity, Shivers, and Turn on the Music. There is your standard dance music ,like Red Zone, to J-pop,like Kiseki. There is also songs that would be hard to fit in a certain genre such as Xepher and Ska Ska No.3. The new battle mode is entertaining but the appeal won't last forever. The online play is better allowing you to actually choose the song this time. This game is definitely not for DDR newbies. The boss songs such as Fascination~eternal love mix and Fascination MAXX will provide a very hard challenge to DDR newbies even on Beginner. The Stellar Master mode has you going from stellar to stellar getting VIP cards. The problem I have with Stellar Master mode is that I didn't feel like my skills were improving. The Dance master mode from Extreme 2 definitely helped me more. Even though the online play is good, there are exclusive songs which is pretty irritating to those without an online adaptor.
Overall, if you are good at rhythm games like Beatmania and Guitar Hero this is definitely worth getting. If you are a newbie to DDR, then you should start off with Extreme 2.