Re-posting this here as I don't feel it deserves it's own thread.Unlockable in-game music:
What if the soundtrack was composed of two versions for every level: maybe an orchestral and electronic one (also possibly varying slightly on the arrangement to make them truly stand apart).
Perhaps you could unlock the orchestral/electronic versions for every level by collecting a special hard-to-get item, like a Music Pagie, or by completing special challenges in-game. It'd make a fun reward to be given the option to change every level's music into something different, but similar.
Perhaps if an orchestra is too expensive, the unlockable electronic version could be an 8-bit/nostalgic/other special genre (like jazz etc.) arrangement. It'd probably be cheaper to produce, but still awesome to listen to. I should patent this idea -- think I'm onto a winner!
- Original thread I posted this in)