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.
Minecraft Breaks 12 World Records. 1  Longest Marathon on Minecraft: 24 hours and 10 minutes, by Austrian gamer Martin Fornleitner playing on a Sony Xperia Play handset. 2  Best-Selling Indie Game: Not including the console versions with big publishers, Mojang has sold 16,176,201 copies on PC and Mac.