I had a go on this last night with some drunk friends and really enjoyed it. I've never played any such thing before.
I didn't like the guitar but that is probably the snobby guitarist in me, but I loved the drum kit. OK it only lets you use one foot, I think a 2 pedal setup would be great for the really hard settings, but apart from that it is a pretty good introduction to rhythm basics, it's a lot like playing a real electronic kit.
My friend had downloaded Interstate Love Song as well which was great fun to sing.