How to play

The user controls the player square using the arrow keys.

• The red square is the player.
• Brown squares are boxes.
• Blue squares are stones.
• Yellow squares are keys or locks -- we fix this in the book.
• Greenish squares are called flux.
• Gray squares are walls.
• White squares are air (empty).

If a box or stone is not supported by anything, it falls. The player can push one stone or box at a time, provided it is not obstructed or falling. The path between the box and the lower-right corner is initially obstructed by a lock, so the player has to get a key to remove it. Flux can be "eaten" (removed) by the player by stepping on it.

How to win

The objective of the game is to get the box to the lower-right corner, like this:

Solution (put your cursor here):   → → → ↓     ↓ ↓ ← ↑     ↓ ← → ↑     ← ← → →     ↓ → →