FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Puzzle Games
Puzzles appear in games in several genres. Many single-player computer games contain puzzles; in action games, the player often has to figure out the boss opponent's weakness; adventure games are full of puzzles, frequently about obtaining inaccessible objects or getting information from other people; even first-person shooters offer the occasional puzzle, figuring out how to get past locked doors and other obstacles. Puzzle design is an essential element of game design, and it's harder than you might think.
In puzzle games, puzzle solving is the primary activity, though puzzles may occur within a storyline or lead up to some larger goal. That doesn't mean that you can offer a random collection of puzzles and call it a game; puzzle games usually provide related challenges, variations on a theme. The types of puzzles offered include recognizing patterns, making logical deductions, or understanding a process. In all cases, the puzzles give the player clues that have to be somehow unraveled or solved to meet the victory condition. Puzzle solving under severe time constraints—as in Tetris—belongs more to the action than to the puzzle game genre. Tetris and the many games similar to it depend more on physical coordination challenges than they do on logic problems.
To be a commercial success, a puzzle game needs to be challenging (but not too hard), visually attractive, and above all, enjoyable. It also needs to be fresh and to offer enough gameplay to justify the purchase price. Although solitaire card games such as FreeCell belong in the class of puzzle games, unless you sell a lot of them together as a collection, people are unlikely to want to pay for them.
