Unfortunately, for those that do share my enthusiasm, there is a kind of glass wall on the path of progress that frustrates many aspiring Android game developers.

Android uses Java to make games. Every Android book, even those aimed at so-called beginners assumes readers to have at least an intermediate level of Java, and most require anadvanced level. So good-to-excellent Java knowledge was a prerequisite for learning Android.

Unfortunately, learning Java in a completely different context to Android can sometimes be a little dull and much of what you learn is not directly transferable into the world of Android anyway.

To add to this that games are arguably more advanced than regular GUI based apps and you can see why beginners to Android game development are often put off from starting.

But it doesn't need to be like this. In this book I have carefully placed all the Java topics you would learn in a thick and weighty beginner's tomb and reworked them into six games, starting from the incredibly simple through to an open-world 2D platformer.

If you want to make games or just want to have more fun when learning Java and Android, it makes more sense, is vastly more enjoyable, and is significantly quicker and more rewarding to teach Java and Android in a game development environment. This book will teach Java with the single overriding goal of learning to develop professional standard games, but this knowledge is also transferable to non-Android Java environments and non-games Android environments. And that's what this book is about.

The first game we build will allow us to introduce some key Java beginner's topics. Code comments, variables, operators, methods, loops, generating random numbers, if, else, switch and a brief introduction to object-oriented programming. We will also see how to communicate with the Android OS, detect screen touches, draw simple graphics, detect the screen resolution and handle different screen sizes. All this will be used to build a simpler variation of the classic Minesweeper type game. Here is one of the screens from that game.

This will be a tap-to-shoot game where the player has to guess the position of the sub', then refine their next shot based on the "sonar" report of the previous shot.

For the second project, we will slightly increase the complexity and move on to 60 frames per second smoothly animated Pong clone. The Java topics covered include classes, interfaces, threads, try-catch blocks, method overloading vs. overriding and a much deeper look at object-oriented programming including writing and using our own classes. This project will also leave the reader competent with understanding the game loop, simple bouncing physics, playing sound effects and detecting game object collisions. Here is a picture of the simple but still a step-up Pong game.

If the Pong game doesn't seem very busy, then the next game will not only be the exact opposite but will also giv e you the knowledge to improve the first two games.

In this project, we will meet Bob. In this Bullet Hell game, Bob will be a static image that can teleport at will anywhere on the screen to avoid the ever-growing number of bullets. In the final game we will also animate Bob, so he can run and jump around an explorable scrolling world. This short implementation will enable us to learn about Java arrays, Bitmap graphics and measuring time. We will also see how we can quite simply use Java arrays alongside what we have already learned about classes to spawn vast numbers of objects in our games.

The objective of Bullet Hell is to survive for as long as possible. If a bullet is about to hit Bob the player can teleport him by tapping the desired destination on the screen, but each teleport spawns more bullets.

This game is a remake of the classic that has been enraging gamers for decades. Guide your snake around the screen and gaining points by eating apples. Each time you eat an apple your snake gets longer and harder to keep alive. In this project we learn about Java ArrayList, enhanced for loop, the Stack, the Heap and the Garbage collector (seriously- it's a thing) and we will also see how to make our games multilingual. Hola!

The game ends when the snake bumps into the edge of the screen or ends up eating part of his own body.

This project, technically speaking, is a big step up from Snake. We will learn how to handle multiple different alien types with unique behaviour, appearance and properties. Other features of the game include rapid fire lasers, scrolling background, persistent high score and a cool star-burst particle system explosion effect.

In this project we are introduced to Java and game programming patterns which are key to writing complex games with manageable code. We will learn about and use the Entity-Component pattern, Strategy pattern, Factory pattern and Observer pattern.

The techniques learned in this project are vital if you want to design your own games while structuring your Java code in a way that allows your games to become more complex and yet keep the code manageable.

In this project Bob makes a second appearance. The game will be a time trial where the player must get from the start point to the exit in the fastest time possible. There will be deadly jumps, moving platforms to navigate, fire pits and collectible coins. Every coin the player fails to collect will add a time penalty.

In this project we learn about the concept of a moveable camera that tracks the part of the game-world that needs to be shown to the player at any given moment. We will also learn some new Java patterns and reinforce the vital knowledge from the previous chapter. Furthermore, we will see how we can design levels as text layouts and then load them in code as playable levels.

There are three levels and the player will choose the level they want to play from a home-screen which will also show the fastest times for each level.

Let's learn a little about how Java and Android work.

Using your preferred file manager software, perhaps Windows Explorer, Create a folder called AndroidProjects. Make it at the root of the same drive where you installed Android Studio. So, if you installed Android Studio at C:/Program Files/Android then create your new folder as C:/AndroidProjects.

Or if you installed Android Studio at D:/Program Files/Android then create your new folder as D:/AndroidProjects.

If you do, click Install missing platform(s) and sync project, accept the license agreement and click Next followed by Finish.

If you get another message like this:

Click Install Build tools…. Then click Finish.

The panel on the left can be changed to various different views. We will need it just as it is for virtually the whole book. This is the Project panel/window. Let's take a closer look.

As you can see there are a few folders and sub-folders. For around 90% of every project, we will only need one folder. The folder I am referring to is the Java | com.gamecodeschool.subhunter folder. It is the one with the SubHunter file in it. The little blue C icon to the left of SubHunter indicates that this file is a class and we will explore classes throughout the entirety of this book. The extension of all class files is .java. The extension for class files is not shown in the Project panel. All we need to know for now is that a class file is a file with code in it.

Notice that below the com.gamecodeschool.subhunter folder (with the SubHunter class file in it) there are two more folders with the same name. These folders, however, are postfixed with the words (androidTest) and (test), respectively. Whenever we add new code files it will always be to the top folder, the one without any prefix, that contains the SubHunter class/file.

Feel free to explore the other folders. We will also be using the res folder in later projects to add sound files and graphics. We will be making brief adjustments to the file in the manifests folder in a moment as well.

The important points to take away from this section is that this is the Project panel and all our code will go in the top com.gamecodeschool.subhunter folder. If you entered a different company domain back in the Starting the first project – Sub Hunter section, then the name of the folders in your Project panel will be different but the exact same principle applies – use the top one.

Let's explore the place where the real action happens – the Editor window.

This is where, as the name suggests, we will edit our code. Typically, we will add multiple code files to the com.gamecodeschool.subhunter folder and add code to them through the editor window. We can have multiple code files ready for editing at once. Have a look at the next image of the code editor as it stands now.

Now, in preparation for the next section, open the manifests folder at the top of the Project panel. You do this by left-clicking on the little triangle to the left of the folder. I have highlighted this in the next image.

Inside the manifests folder, there is a single file, AndroidManifest.xml. Double-click the file and notice that it has been opened in the editor window and that we now have two tabs so that we can quickly switch between AndroidManifest.xml and SubHunter.java. This next image makes this clear.

Also, note that you can now see the .java extension of SubHunter. Now that we know where our code files will go, how to get to them and how to edit them we can move on to the Sub Hunter project.

Follow these simple steps to run the game on the default Android emulator.

You're done. Here is what the running game looks like so far:

Clearly, we have more work to do but it is a good start. Let's see how to do the same on a real device and then we can go about building Sub' Hunter further.

The first thing to do is to visit your device manufacturer's website and obtain and install any drivers that are needed for your device and operating system.

The next few steps will set up the Android device for debugging. Note that different manufacturers structure the menu options slightly differently to others. But the following sequence is probably very close, if not exact for enabling debugging on most devices:

We are now ready to learn some Java and add real code to the Sub' Hunter project.