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.
Gaming addict breaks world record for longest Call of Duty session after playing non-stop marathon for 135 HOURS. 1  Okan Kaya, 28, from Sydney Australia, lasted five and half days to break world record.  Okan smashed the previous record for continuous gaming which stood at 120 hours.