When I played this for the first time I was pretty confused how it worked because there was only one turntable and a mixer which acts like you're controlling two. If this would have made sense, it should have been two turntable controllers with the one mixer. On first glance, it's more confusing than actual DJing.
Also all of the "trance" mash-ups are pretty meh. I can understand that they'd have to do that because the typical trance mash-up is usually a harmonic mix and does not require as much turntable-ism that is present on DJ Hero.
Though that's supposedly an Armin van Buuren DJ game coming out or something and even though that's going to be mostly European trance, I have my doubts it might be executed well.