## Review: Simon Tatham's Puzzles

Sometimes, you stumble across something that’s just too good not to share. By sheer chance, I stumbled across one such collection over a decade ago, and it’s stayed with me since.

Simon Tatham’s Puzzles is a collection of puzzle games, that are perfect for killing time. There are rules about what can be included, namely that all games should only generate solvable challenges.

Below I’ve listed a few of my favorites.

## Solo

Solo is the name for the classic Sudoku puzzle. All squares in a grid must be filled in with numbers, such that the same number does not appear more than once in any row, column, or box. It offers difficulties ranging from 4x6 grids to 9x9 with jigsaw pieces, allowing for a lot of variety of play.

## Pattern

Pattern is a nonogram (Picross) puzzle. At the top and side of the grid, there are sets of numbers. Each number represents a set of cells in the grid that are marked. There has to be at least one unmarked cell between marked groups.

## Mines

This is an implementation of the classic game Minesweeper. A series of mines are hidden under a grid. Any cell contains either a mine, an empty square, or a number, where the number denotes the number of mines in the eight cells adjacent to it. The goal is to mark all the mines with flags, while not accidentally uncovering any.

## Towers

This one is less well known, and requires a little lateral thinking. Each spot in the grid holds a tower of a given height. No two towers in the same row or column can have the same height. Around the edges of the grid are numbers, showing how many unique towers are “visible” looking from that direction. This forces you to think about which towers might be hiding other ones.

## Black Box

A group of balls are hidden inside a black box. You can’t see inside the box directly, the only way to observe the contents is to shoot a laser into it and see where it comes out. You spend a lot of time tracing lines, determining where the lasers hit the balls, where they get reflected, and where they make it out safely.

## Unequal

Another number-grid game, this time the numbers have to adhere to the comparison operators scattered throughout the edges.

## Range

I saw this game popularized as 0hn0. Basically, each cell with a number can “see” that many unmarked cells, including itself, and all the unmarked cells must be connected.

## Unruly

This game was similarly popularized as 0hh1. There can be no more than three cells of the same color in a row, and each row and column contains the same number of black and white squares. I enjoy the additional challenge that’s configurable (default in 0hh1), where no two rows or columns are the same. It provides an additional set of rules to remember.

## Net

By far my favorite game from the puzzles collection is Net. The rules are simple - all of the nodes have to be connected in one network, and there can’t be any loops. The real challenge is when you add wrapping to the mix, and the entire network flows from one side of the grid to the other, looping around. I’ve spent many hours relaxing with this particular puzzle, just solving challenge after challenge, as I find it very soothing.