Did this remind anyone of Hollywood Medieval on the Atari by Douglas Crockford? Much simpler than this, you moved through hallways or streets, pressing the fire button to change musical phrases. There's supposedly an ending but I can't find a video of it.

Simple demo: https://www.youtube.com/watch?v=AnktY6gOmaA

Detailed discussion: https://www.youtube.com/watch?v=BLXL8jwg-tk