Boxyboy

Sokoban takes place in a warehouse viewed from above and composed of walls and floor squares. A floor square may be empty, occupied by the player, or occupied by a box. Some floor squares are storage locations. The number of storage locations equals the number of boxes. The objective of the puzzle is to push all boxes onto storage locations.

The player can move one square at a time, either horizontally or vertically, onto an empty floor square. Boxes and walls block the player's movement, but the player can walk up to a box and push it to an empty square directly beyond it. If a box is pushed against a wall or another box, it does not move. Pulling boxes is not possible.

In 1981, Hiroyuki Imabayashi created the Sokoban video game for the NEC PC-8001 as a hobby, featuring text-based graphics and five original levels. He had long been intrigued by the movement of a character pushing luggage in the action game Aldebaran #1 (1980), in which luggage was used as an obstacle to block radiation; he implemented that movement as a puzzle using BASIC in spring, envisioning a warehouse setting where incorrect box placement could make further progress difficult or even impossible. In autumn, he completed the design of levels that proved challenging even for his friends. That winter, his wife's parents owned a record store, and there was talk of setting up a small computer section in it; at the time, a salesman who happened to see the game suggested to Imabayashi that it had commercial potential.

Imabayashi then began preparing Sokoban for commercial release; using an NEC PC-8801 in the computer section, he decided on the design, enhanced the graphics, and expanded the level count to twenty. He founded Thinking Rabbit to market Sokoban, which became the company's first commercial title. The timeline of these events varies across sources: official records report a 1982 founding and a December 1982 release, while other sources date these events to 1983, placing the company's founding in spring, its debut or incorporation in June, and the release in April, May, or June.

The first Sokoban title became a bestseller in Japan, with over 50,000 copies sold by October 1984. Junji Tanaka wrote that the first level of the PC-8801 version perplexed puzzle enthusiasts upon release. Titles for Japanese home computers, such as the NEC PC-9801 and Sharp X1, were said to have sold more than 100,000 copies combined. The MSX version alone, published by ASCII, sold over 400,000 copies and was considered a commercial success.

S. release, Soko-Ban, had surpassed 50,000 units by mid-September 1988. By c. 1996, after 13 years of availability, the series had sold over one million copies.

Sokoban was regarded in 1990 as a pioneer in puzzle games. It sparked a "puzzle game boom" in the Japanese personal computer market starting in 1983 and continuing for a time. A 1984 magazine reported that the first Sokoban game was so groundbreaking that programmers at several software houses described it as an eye-opening experience. In the decades since, the series has attracted many enthusiasts in Japan and overseas.

The game's core mechanics have been replicated in numerous clones across a wide variety of platforms, including the web. The Sokoban community has created thousands of levels distinct from the official releases, freely available online and ranging in difficulty.