Nope, any region, according to some reports i have it works well on ntsc genesis and megadrives. And on my nstsc grnesis 1 too. Looks like a fpga emulation problem.
They found the issue. I guess the game needs a unique serial number instead of all 0's. It identifies the game by the serial number.
Why not identify a game by "Domestic or International name" from ROM header? Looks more logical and easy. Not sure how i can generate an serial number and not hit another game SN.
One of the MiSTer FPGA devs found a work-around and asked if you could give the game a unique serial number.
I'm passing along the Dev's comments:
The bus arbitration in our core is not ideal most games don't care, but some do, so this one needs a FIFO tweak to make it behave correctly but to do that, I have to be able to uniquely identify the game, which means the serial has to be meaningful, not all 0's