A virus is a microscopic organism that can replicate only inside the cells of a host organism. Most viruses are so tiny they are only observable with at least a conventional optical microscope.
Recognized by the Guiness Book of World Records as the MMO with the longest play time per player, and easily the oldest game on this list (launching four years ahead of World of Warcraft, way back in 2001), Runescape deserves mention because it's one of the most updated and popular games of any kind on the planet.
You got nothing on this game. First off, Longest is in its title. Second, this beast has been known to take several seasons to play (spring until fall). So, when the other Mamby-Pamby game times like several hours get tossed about, The Longest Day scoffs at your limited concept of LONG. I could have several plays of 2038 wrapped even before the setup for TLD was completed.