The History of Crate Pusher
A puzzle about pushing crates in a storeroom, and why it has a different name here.
An Idea from 1981
The principle of pushing crates onto marked places, one at a time and never pulling, was invented in 1981 by Hiroyuki Imabayashi. In 1982 the Japanese company Thinking Rabbit published it as a computer game under the name Sokoban.
The simple rules turned out to hide real depth: even small rooms can need long, carefully planned sequences of moves, and computer scientists have shown that solving such puzzles in general is very hard. The idea has since been taken up by countless puzzle games.
Why a Different Name
Sokoban is a registered trademark of Falcon Co., Ltd. PaperGames has no connection with Falcon or with the original game and therefore uses a name of its own: Crate Pusher. The same is done with Calcudoku, which is played under its own name for the same reason.
None of the levels here comes from the original game or from any level collection. Every level is generated by PaperGames' own program when you ask for one, built backwards from the solved position and checked with its own solver.