Throughout this book, we'll be distilling our game development dreams down to small, bite-sized nuggets instead of launching into any sweepingly epic open-world game. The idea here is to focus on something you can actually finish instead of getting bogged down in an impossibly ambitious opus. This book will teach you how to build five games, each of which focuses on a small, simple gameplay mechanic. You'll learn how to build discrete pieces of functionality that you can apply to each project, filling the games out to make them complete experiences. When you're finished, you can publish these games on the web, Mac, PC, and Linux systems. If you spring for an additional software license for one of Unity's many add-ons, you may be able to publish your games for other platforms, including home video game consoles.
The team behind Unity 3D is constantly working on packages and export options ("snow tires") for other platforms. At the time of this writing, Unity could additionally create games that can be played on iOS, Android devices, Xbox One, PS4, and Wii U. Each of these tools is an add-on functionality to the core Unity package, and comes with an additional cost, while console development usually requires a developer relationship with the platform owner. These licenses are constantly in flux, however, and the mobile development add-ons that used to cost an additional fee are now free. By the time you read this book, who knows? To be safe, we'll stick to the core Unity 3D program for the remainder of this book.
With the initial skills that you learn in this book, you'll be able to expand on your knowledge to start building more and more complex projects. The key is to start with something you can finish, and then for each new project that you build, to add small pieces of functionality that challenge you and expand your knowledge. Any successful plan for world domination begins by drawing a territorial border in your backyard; consider this book as your backyard.