If you're making the actual game, and can therefore implement the virtual machine in native code on the host machine (instead of in a shader on the GPU as here)

If you're making the actual game, and can therefore implement the virtual machine in native code on the host machine (instead of in a shader on the GPU as here) then you can very easily get 10 to 100 MIPS performance in an emulated machine with a very simple emulator. Such as https://github.com/brucehoult/trv https://github.com/brucehoult/trv Bear in mind that the original Mac was roughly a 2 MIPS machine and an early Pentium or PowerMac 100 MIPS.