You must run as root in mountain lion:
In Terminal simply type: sudo "/Applications/WBFS for MacOS X.app/Contents/MacOS/WBFS for MacOS X"
Using Terminal simply type: sudo "/Applications/WBFS for MacOS X.app/Contents/MacOS/WBFS for MacOS X"
I didn't know they made an MSU cart for the Genesis.... I knew about the SNES one and the library for that is rather large but the Genesis one has very few games