For those of you that need a western comparison, I suppose this game is most similar to DJ Hero, but even that is a pretty bad comparison as the control schemes are completely different. It's your standard rhythm game though, notes flow down the screen and you hit the buttons in the right order not to fail the song.
Speaking of the settings, there are 3 difficulty levels in Sound Voltex Booth; Novice, Advanced and Exhaust. I've not had too many runs of this game yet as I've only just started playing, but even on Novice the game can still be a bit of a challenge depending on the song.
As you can see in the above image, the Exhaust mode is locked, so I hope to god you brought your e-amusement pass card. For those of you who don't know, an E-Amusement pass looks like this.
So if you ever find yourself in Japan, give this game a spin. If you don't ever come to Japan, or never plan to then cross those fingers and hope that they release a console version for you to import, but I don't think it's likely.
Just as a little bonus I've uploaded 2 gameplay videos so have a lookie see.