Smoked Salt Interactive is a 3d visual music remixer for Win/Mac (iOS soon), featuring new music by Dev79. This is part of a series of visual music games I've been making, each one based around a piece of music that's chopped up and re-sequenced to be manipulated in real time.
Game Page (pay-what-you-want, no minimum)
As I make these, I'm developing a system for creating interactive music in Unity, which is also available free and open-source (hosted on GitHub). If you're interested in interactive music, I'd love to hear what you're making and what kinds of tools you'd like to see to aid in your process.