Question about running other c, c++ softwares

is there a way to run a nintento emulator (which i have the source code in c++) from within arduino,,,, and use it as a videogame ?

No.

how do other fpga's do ? i have seen an altera cyclone 2 running pc engine games into tv....

The Arduino uses an Atmel AVR MCU, not an FPGA!

i am not a pro....

i know that i can add, sound and video to arduino... and even more memory...

why even so,,, would it not be possible?

why even so,,, would it not be possible?

Why will you not be told?

The processing power is not good enough there is not enough memory, the CPU architecture is not the same.

i know that i can add, sound and video to arduino

Only in a very limited way.

and even more memory.

You can't add more program memory on anything but a mega.