Sonic & Knuckles (Sega Genesis/Mega Drive) was one of my favorite video games a kid, and I still love playing through it from time to time. I played it so much back then that I could play through many parts nearly perfectly, while accessing every secret area and power-up.
"Glowing Spheres" was my favorite bonus stage in the game, but I've never heard its theme music remixed before. As I started thinking about it, I realized that it would fit quite nicely in a trance style, in the vein of progressive DJs such as Paul van Dyk and Armin van Buuren. This is the result.