Sokoban is japanese for ‘warehouse keeper’: 倉庫番.

This puzzle game was originally invented in Japan in the early 80’s. You have to push crates to their proper locations with a minimum number of moves. - online / wikipedia

• as codingame puzzle
• part of Syntax Terror Demo

Algorithm

The problem of solving Sokoban puzzles was first proved to be NP-hard. Further work showed that it was significantly more difficult than NP problems; it is PSPACE-complete.

Sokoban is difficult not only because of its large branching factor, but also because of its large search tree depth.

• from rosettacode
• Sokoban: Reversed Solving
• Solving Sokoban (Thesis) / SO
• Research Project: Solving Sokoban Puzzles
• Sokoban Solver