Sokoban ("warehouse keeper") is a is a classic puzzle game created in 1981 by Hiroyuki Imabayashi, and published in 1982 by Thinking Rabbit, a software house based in Takarazuka, Japan. In 1984 the ASCII Corporation published a version produced by Khaled Bentebal. It was the basis of numerous clones in the later years. It is set in a warehouse. On each level, the player must push crates (from square to square) to get them onto designated spots; once each crate is on a marked spot, the level is complete. Crates can only be pushed one at a time (so two crates next to each other cannot be pushed together), and cannot be pulled--so it's possible to get a crate stuck in a corner, where it cannot be retrieved! By the last levels, you must plan 40 steps in advance.