There once was a game called HarvestCraft...
It started out simply enough, but functionality continued to be added, improvements which sometimes owed their existence to improvements in the hardware.
The base scale was made perpetually smaller, which allowed for finer precision for everything.
Weather was added, which then affected local climates.
Grain varieties were added. Their growth depended upon weather and climate.
Enough plants, animals, fungi, archaea, etc. were added to make for a self-sustaining biosphere.
Fossil generation was added, though not much was done with it.
Organisms were made to be assemblages of one or more cells.
Later, the organelles pack was added, further fleshing out the cells.
DNA was added, which allowed for tree-tracing the relations among organisms, for those interested.
The virus patch was added.
The edge walls were removed in favor of a finite plane that wrapped around on itself.
Proper gravity was added, though its only noticeable effect was that it created tides.
NPCs were given general AIs, and their reproduction - and everyone else's - was eventually upgraded to include an entire proper development cycle. Aging was also added.
Eventually, though, the players grew tired of this game, too, and left, though the server was left running.
No one has yet returned to shut down Earth.