Puzzle Advent Calendar

Puzzle Advent Calendar is a free puzzle calendar with 24 doors, one for each day of December. Each door hides a sliding tile puzzle: slide the numbered tiles into order, with the empty square as your only space to move. Doors get harder as the month goes on, and everyone gets the same board behind each door, so you can compare your moves with friends. Outside December every door is open for practice, so you can try the whole calendar any time.

How to play

1. Open a door from the calendar. Each door is a 3×3 sliding puzzle.
2. Tap a tile next to the empty square to slide it into the gap. Arrow keys work too.
3. Put the tiles in order from 1 to 8, with the empty square in the bottom-right corner.
4. Solve the puzzle to mark the door as done, then go back to the calendar for the next one.

Tips and strategy

• Solve the top row first, then the left column. Leave the last two tiles of the bottom row until the end.
• Only the tile next to the gap can move, so think a few slides ahead before you move anything.
• If you get stuck, use Undo to step back to a position you understand, or Restart to begin again.
• Later doors need more moves. Play the early doors first to learn the patterns.

Questions