Well first off you need to download an emulator such as JNES or ZSNES. Then you need to download the rom of whatever game it is you wish to play. But be warned, almost every site with emulators or roms has anime porn. And also, I feel this is worth mentioning, it is illegal to download roms and keep them for over 24 hours. Appearently if you own the original it is perfectly legal to get the rom and keep it as long as you wish. I do not know how accurate this legal business is but I hope it helps either way.