Ultima II - The Return of The Enchantress
Screen shot from PC version of Ultima II
Ultima II was released in 1982. This game was very similar to  its predecessor. The game looked different in cities, and the first primitive  form of interaction with all people in the world (except monsters) was  introduced. Richard Garriot applied his newly-gained knowledge of Assembler  in this game, which enhanced the speed and performance quite a bit.
The story in Ultima II is almost the same as in Ultima I, but it is this time  taking place in our very home world: Earth. Mondain's apprentice and, as  it would turn out, lover, the witch Minax has stepped forward to  avenge the destruction of the Gem of Immortality and the death of her  master. Her power has grown to untold magnitudes and she could   prove to be even more difficult to stop than Mondain. In fact, she  has already won.
  The holocaust happened sometime after 2000AD. The vast majority of Earth's  population was wiped out by the evil witch. Some kind of divine force has  created something that might help in your quest to set things right, though.  A set of strange blue portals appear and disappear at seemingly random  locations and times on Earth's surface. It has now been clearified that  these portals can be used to travel through time. Someone must go back  to the time before the holocaust and finish off Minax before she gets the  opportunity to do the same to the world.