Sokoban — Box Pusher

Sokoban — Japanese for 'warehouse keeper' — was created by Hiroyuki Imabayashi in 1981 and published by Thinking Rabbit the following year. The rules fit in one sentence: push every box onto a goal square. You can only push (never pull), only one box at a time, and only from the square directly behind it. Those three constraints are the whole game, and they are enough to make Sokoban one of the most studied puzzle families in computer science — solving it in general is hard enough that it is still used as a benchmark for planning algorithms.

This edition ships 40 hand-authored puzzles in the compact Microban tradition: small rooms, a handful of boxes, and one precise idea per level, with difficulty rising steadily from tutorial-simple to genuinely knotty. The game counts moves and pushes separately, remembers your best move count for every level, and gives unlimited undo, so an accidental push never forces a restart. Solved levels and your position are saved in your browser, and a level-select grid lets you jump straight to any puzzle.

The skill that separates beginners from solvers is spotting deadlocks before they happen. A box pushed into a corner is frozen for good unless that corner is a goal, and a box pinned against a wall can only ever slide along that wall. Work backwards from the goal squares: decide the order the boxes must arrive in, and make sure you can get behind each one when its turn comes. Positioning yourself is half the puzzle.