Hi
Rap City AKA Rap Quest was produced by THQ beginning in early 1991 and placed under contract development with Sausalito-based Equilibrium (Sean Barger, owner
http://gdri.smspower.org/wiki/ind...)
A 1 meg Gameboy version named Rap Quest (THQ P/N unknown) was originally scheduled to be submitted to Nintendo mid-October but the date slid to the end of January 1992.
A 4 meg SNES version of Rap Quest (THQ P/N 19575-03001) was originally scheduled to be submitted to Nintendo December 1st but the date slid to the end of February 1992.
Ultimately, neither game was released.
Sorry, I can't remember much else...