Chapter 14

Ten Game Engines and Tools

In This Chapter

Finding good game engines

Getting software for creating your own image and sound resources

Investigating tools for promoting and monetizing your games

A game engine is a pre-built set of tools to help you build a game without having to reimplement tasks that are common to almost every game. A lot of good game engines are available for Android; I’ve listed a good sampling here, though it’s certainly not exhaustive.

You also might want to take advantage of some freely available SDKs that can improve non-game aspects of your game product — such as marketing and analytics. I’ve included some tools here that can help you promote your game to other users and gather information on when and how your game is being played.

Also, if you want to make your own image and sound resources, you’ll need tools that are up to the task. If you already own great image-editing software and know how to use it, that’s great. But if not, and you’re on a budget, I point you toward some formidable free resources that can help you do the needed world-building.

libgdx

This game engine allows cross-platform game development for both Android and desktop games. Just a few lines of code allow you to run your game on your desktop machine, which makes prototyping and testing much easier. libgdx has Box2D support for physics, and TMX tilemap support, which allows for easy, rapid development of games that use tiles, such as RPGs.

Some very popular games on Google Play were developed using libgdx, and I have used it for my physics-based game Save the Egg. It will definitely save you a lot of time and effort in the making of a professional game, and it is pretty well documented with a large community of developers. It’s an easy download (see Figure 14-1.) See

http://code.google.com/p/libgdx

AndEngine

This is another great free game engine for Android, developed by Nicolas Gramlich (see Figure 14-2). It includes many of the features you want in a game engine and has an active development community at www.andengine.org/forums. See

https://github.com/nicolasgramlich/AndEngine

Unity

Besides the free engines, powerful proprietary game engines exist for use with Android. Unity, for example, has been around for a long time and has extended its game engine for use with Android. The baseline version is free to use; upgrades to the Pro version are available, as is support for many more optimizations and higher-level features. See

http://unity3d.com/unity/publishing/android

OpenFeint

Often you’ll want to include features that allow players to recommend the game to one another and compare their performance via shared leaderboards (ranked listings of scores from other players). OpenFeint is a free SDK that supports friend recommendations, leaderboards, and achievements.

Social features can often take your game to the next level of popularity (and profitability!), so using these freely available tools and help files just might be a very good idea (see Figure 14-3). See

http://support.openfeint.com/dev/welcome

Flurry

As feature-rich as the Google Play developer console is, it’s been slow to offer native support for a lot of usage statistics and bug reports. Even now, the console could use some help in that department; there’s still a lot of value in including analytics in your game to help improve (and possibly monetize) it. Flurry offers a painless way to build in analytics.

With just a couple of lines of code, Flurry provides a treasure trove of default user data — for openers, number of sessions per day per user and length of sessions. And if that’s not enough information for you, Flurry allows you to capture information about custom events — say, how many attempts it takes users on average to defeat a particular level or enemy, or how often they use a particular set of controls. Information is power, and gathering detailed analytics may help you improve your game immensely (see Figure 14-4). Flurry now also provides an ad network and other monetization tools, so that’s something else you might want to look into. See

http://www.flurry.com

Audacity

Elsewhere in the book, I mention the options of either purchasing sound effects and music or producing your own. You really should try making your own sound effects, and read up on the history of sound effects in movies like Star Wars. You’d be surprised at how some of them are made!

In any case, if you do go the roll-your-own route, Audacity is a great free tool for editing audio. (See Figure 14-5.) It’s been around a long time and has a very avid user base. See

http://audacity.sourceforge.net

sfxr

This is a cool little tool that I came across a while back. (See Figure 14-6.) You can use it to create common sound effects from old-school-style video games, like coin-ups, laser blasts, and jumping sounds. If you’re working on retro games, this is a must. Even if you’re not, you may find a place for the kinds of effects generated by sfxr in your game. See

http://code.google.com/p/sfxr

GIMP

GIMP is short for GNU Image Manipulation Program. It’s a powerful, free image editor on par with many proprietary programs (see Figure 14-7). The last time I used it, the learning curve was a bit steep. If you’re working with fairly complex images and effects, you’ll want to invest the time in learning GIMP. Otherwise you might want to use a simpler, friendlier tool for your image needs. See

www.gimp.org

Inkscape

If you’re comfortable working with vector graphics, Inkscape is a great little tool for image creation and editing. It’s pretty user-friendly and has a lot of features. (See Figure 14-8.) You can export your creations to .PNG format for use in your Android games. Work through some of the tutorials and you’ll find that you can create some pretty nice images even if you’re not a professional artist. See

inkscape.org

AdWhirl

In Chapter 11, I mention ad mediation — the process of using multiple ad networks in a single app, controlling the ratios to maximize your profit from ads. At any given time, some networks may be generating more revenue than others, so it may make sense to monitor and adjust which ad provider’s ads are being served up by your app. (See Figure 14-9.) This may sound confusing, but it’s really not — especially not when you have a good tool to help you handle it.

AdWhirl is a free tool that allows you to use a wide cross-section of ad networks in your game, as well as house ads promoting your other apps. If you’re thinking at all about monetizing your game via ads, you’ll want to look into AdWhirl. See

adwhirl.com