Outstanding! Non-Japanese-reading fan here, so don't let the menus discourage you! (there are a lot of guides out there)
I am still having a lot of fun unlocking all the module content (outfits and other characters). At this point I still need to get Hard-Great on a few more songs and get the swimsuits for a few more characters.
Graphics & Sound:
Beautiful scenery and there are really cute outfits for Miku to wear!! (^o^). I also have to say that the music is very catchy and cute - if you are a fan of j-pop and cute Japanese culture then scoop up this game!
Gameplay:
Once I got a guide for what the menus meant (and guides are very easy to find, so don't let a language barrier stop you from getting this game) it became very easy to navigate.
I also enjoy rhythm games, so I find the gameplay enjoyable (match the buttons to the beat ^^). Especially since I cannot understand Japanese story modes; therefore, this game has been a great import for me.
Another thing to keep the game alive after you have completed the modules, is the ability to create your own music video by uploading an mp3 and then frame by frame directing Miku's dance moves, facial expressions and the camera angel.
* This part has proved to be quite difficult, despite some guides being available online. However, I am pushing onward (hopefully one day I will finish my video).
In this mode you can also play other people's custom made videos - however, again I have not figured out how to do this.
The only thing I suggest is that this part of the game be more intuitive - I would love to play other people's creations as well as display my own -- hopefully soon ;)