I'm designing a video game! I already have four tracks on the soundtrack done and I'm working on a fifth at the moment. I want to add in an easter egg/hidden feature which will play chiptune mixes rather than the orchestrated soundtrack.

As far as I can tell from doing research online, there are two ways to go about converting a song to a chiptune:

1. writing the entire song in famitracker or a 16 bit equivalent from scratch. I'd rather not, since I already wrote the songs in Musescore and I don't want to go through all that effort again in a brand new program just for an easter egg.

2. Load up the MIDI for the song in GXSCC and record with audacity. The problem with this is that songs put through GXSCCC are absolute GARBAGE. They sound awful.

I also tried finding a chiptune soundfont that I could install in a MIDI sequencer but I couldn't find any that were licensed under Creative Commons.

Anyway, what I need to know is how can I mix a MIDI song into a chiptune without using GXSCC? I'd appreciate any advice you have!