Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Lemmings is a puzzle computer game developed by DMA Design (now Rockstar North) and published by Psygnosis in 1991. Originally developed for the Commodore Amiga, Lemmings was one of the most popular computer games of its time, and several games magazines praised the game, giving it some of their highest review scores at the time. The popularity of the game led to development of numerous ports to other systems, including most recently ports to the PlayStation Portable, PlayStation 2, and PlayStation 3 in 2006 and 2007, and the creation of several sequels. The behavior of the creatures in Lemmings is based on the supposed behavior of real lemmings, who by urban legend are believed to go on migrations en masse that eventually lead to disaster. The basic objective of the game is to guide lemmings to a designated exit through a number of obstacles that prevent the player from winning.