sadly, emulator in WP8 & WinRT is inefficient.
emulator normally uses dynarec/JIT compilation to speed up execution. unfortunately, JIT compilation is not possible in WP/WinRT, because WP/WinRT doesn't allow writable executable memory. (same thing with non-jailbroken iOS, they don't allow writable executable memory)
the result is, all emulator in WP/WinRT are currently using interpreter mode, which is very slow, and can fry your phone pretty fast :D
emulators for GBC, GBA, SNES, Genesis, can still run full speed on WP/WinRT, although they will suck your battery dry because they use 5-7x more power than other platform that support dynarec (android, jailbroken iOS).
emulators for PSX, PSP, NDS are clearly unplayable on WP/WinRT, unless you have a very _very_ powerful device.
Any specific reasons as to why such a difference in Latin American region?
my vision vomes true
we are comming lagoid for squzing u and punching u and terminate u from the universe
we r the windows boys