Karateka

When you get to Mariko, run to her, don't walk. If you do walk, she will think you are trying to kill her, and she will kill you in self-defense.

On the second level entering the castle, a bird comes out before each new guard and takes two arrows unless you de feat him. When the music warns he's coming, try switching to keyboard mode. This will give you an advantage, since the key board is more responsive than the joystick.