The Nintendo Entertainment System (NES), or the so-called "Red and White Machine," is already a classic on its own. And now, this green-version emulator, which is only 15M in size, adds even more charm to it.
This emulator includes over 80 games, all of which are classics and can be considered the collective childhood memories of a generation.
The keyboard/joystick settings can be found under "Settings" -- "Input Device." One thing to note is that when setting it up, numbers will be displayed. For example, if you set "W" as "Up," it will show "38".