Mega Drive games that can't handle simultaneous speech and music

Virtual Bart is a later game with huge amounts of voice samples that play over the music fine. So it can't be a hardware issue.

 

You mean the MD or the SNES version?

In any case, for SNES games the issue was that besides the SPC700 limitations per se being an annoyance, Nintendo made their own sound engine (which was even more retarded than the hardware design) and outright refused to let developers to use their custom engines. This means that pretty much all official SNES games are using a shitty sound engine because Nintendo was stubborn. Does anybody know of any exception to this?

(curiously, Nintendo pulled off the same crap with the N64 and the microcode for video rendering, and eventually had to give up because developers kept complaining that the microcode they provided was too slow)

 

Last I read about it, Tales of Phantasia streamed its voice samples through a modified or custom sound driver, but I'm not quite an expert on it, sorry. It's this sort of thing that made me very disappointed with SNES Mega-Lo-Mania however.