Pearl – Draw a Single Closed Loop – Puzzle Game



In Pearl, you are presented with a grid of squares. Your job is to draw lines between the centres of horizontally or vertically adjacent squares, so that the lines form a single closed loop. In the resulting grid, some of the squares that the loop passes through will contain corners, and some will be straight horizontal or vertical lines. (And some squares can be completely empty – the loop doesn’t have to pass through every square.)

Some of the squares contain black and white circles, which are clues that the loop must satisfy.

A black circle in a square indicates that that square is a corner, but neither of the squares adjacent to it in the loop is also a corner.

A white circle indicates that the square is a straight edge, but at least one of the squares adjacent to it in the loop is a corner.

Pearl is an implementation of Masyu. The inventor of the puzzle game is Nikoli, a Japanese publisher that specializes in games and, particularly, logic puzzles.

Game modes:

  • 6×6 – Easy
  • 6×6 – Tricky
  • 8×8 – Easy
  • 8×8 – Tricky
  • 10×10 – Easy
  • 10×10 – Tricky
  • 12×8 – Easy
  • 12×8 – Tricky
  • Custom mode

Below is a short tutorial showing you how to download and compile the latest source code for this game, and the other 38 games in the puzzle collection. The tutorial takes place in Linux, using the Ubuntu 17.10 distribution, but the procedure will be the same, or very similar, for other Linux distributions. If you find the tutorial helpful, please give the video a like and subscribe to our YouTube channel.

Besides the main 3 operating system, the puzzle collection has also been ported by contributors to Palm, Android, Symbian 60, iPhone, iPad, and the Windows Store.

Developer: Simon Tatham, Richard Boulton, James Harvey, Mike Pinna, Jonas Kölker, Dariusz Olszewski, Michael Schierl, Lambros Lambrou, Bernd Schmidt, Steffen Bauer, Lennard Sprong, and Rogier Goossens
License: MIT
Written in: C, Java, JavaScript

Back to the Puzzle Collection