A platform game (or platformer) is a videogame characterized by requiring the player to jump to and from suspended platforms or over obstacles. Besides having jumping actions that are central to gameplay, other jump mechanics may be employed, such as swinging from extendable arms, as in Ristar or Bionic Commando, or bouncing from springboards or trampolines, as in Alpha Waves.
Platform games were at one point the most popular genre of videogame. At the peak of their popularity, it is estimated that between one-quarter and one-third of console games were platformers1. No genre before or since has been able to achieve a similar market share. As of 2006, the genre is far less dominant, representing a 2% market share (compared to 15% in 1998)2 but still commercially viable, with a number of games selling in the millions of units.