Free The Key
About This Game
Slide the timber aside and drive the golden key out through the gate.
A sliding block puzzle in a buried temple. The golden key is boxed in behind a wall of timber, and the only way out is a gap in the right-hand wall - so shift the blocks aside, one at a time, and drive it through.
Blocks slide along their own grain and nothing else: a block laid across moves left and right, a block stood on end moves up and down, nothing turns and nothing lifts over anything. Drag one and it stops dead at the first thing in its way, so clearing the path in the right order is the entire puzzle.
Forty-five doors, and not one of them was placed by hand. Every level was found by enumerating every position its blocks can reach and picking one at a measured distance from the exit - which means each is solvable by construction, and the move count on its tile is the true minimum rather than a guess.
The opening doors are four blocks and two moves; the last is thirteen blocks and forty-six. A hint, when you want one, is worked out on the spot by the same solver that proved the level, so it still helps on the twentieth move when you are nowhere near the intended line.
Undo costs nothing and restores the counter with it, three stars for matching the minimum, and progress is kept between visits.
How to Play Free The Key
- Drag a block
- Slide it along its own direction until it stops.
- Z or Undo
- Take back a move. The move counter goes back too.
- H or Hint
- Show the next move of a shortest solution.
- R / Esc
- Reset the level / menu.
Rules
- Slide the golden key out through the gap in the right-hand wall of a 6×6 board. The key always sits on the third row and is two squares long.
- Each block slides only along its length: across-blocks left and right, upright blocks up and down. Nothing turns or jumps.
- A move is one slide of any distance. Each level's par is the true minimum number of moves.
- 45 levels, from four blocks and two moves to thirteen blocks and forty-six moves.
Scoring
- Three stars for matching par, two for coming in close to it, one for finishing. Three stars also earns an extra hint.
- You start with three hints. A hint is worked out from your current position, so it helps even after you have left the best line.
Tips for Free The Key
- Work backwards from the exit: list the blocks on the key's row, then the blocks stopping each of those from moving.
- Moving a block further than it needs to go is free in moves but can trap another one. Slide only as far as the next block needs.
- Undo costs nothing, so try a line and step back rather than restarting.
- Save hints for long levels. Matching par on an early level is the way to earn more.
If You Like Free The Key
- Car Jam Solver – Cars that drive only along their length, cleared from a jammed car park in the right order.