One Game, Everywhere

Gone are the days where you can make a game and publish it to a single platform and expect to be successful. Like any business that sells consumer products, you need to go where the people are. That means the games you make should run on a multitude of different platforms and accept any number of different input types. There’s also one more catch: your players expect to be able to share their game data across all of these different platforms, especially if they are paying for your game multiple times. With that in mind I have outlined what I call “responsive game design,” which is modeled loosely after some of the core concepts of responsive web design. It’s also a framework that will help you think about enabling your games to scale across multiple platforms.

Applying Responsive Design Concepts To Games

On the web, responsive design is a set of guidelines and best practices that help websites scale from desktop to mobile. Web developers discovered early on that it was too difficult to maintain separate designs for desktop and mobile so this solution allows a site to re-adjust to any resolution based on a set of ideal screen sizes. While responsive design on the web focused solely on adapting a site’s visual design based on common viewports, the notion of responsive game design builds on this concept to include other key aspects you need to consider when making multi-platform games.

Responsive game design can be summed up in the following key requirements:

1. Game graphics and UI support multiple resolutions
2. Game mechanics work across multiple types of input
3. Publish to multiple platforms with the same codebase
4. Saved data is synced across all platforms

While most of these are already best practice for games in general, the collection of them represent a guideline for game designers moving forward to help reach the broadest audience possible.

1. Scaling Game Visuals Across Different Resolutions

If you come from desktop game development this is not going to be a big shock to you since it’s common practice to support multiple-resolutions and varying computer performance. While mobile development is relatively new in this space, over the past few years, mobile device resolutions have tended to normalize around a few key aspect ratios (3:2, 4:3 & 16:9) allowing the same desktop game concepts to be applied:

• Build for aspect ratios not fixed resolutions
• Create simplified, dynamic UI that can adapt to different resolutions
• Have degradable graphics that can adapt to the power of the device

It’s also important to note that optimizing a game’s graphics goes well beyond just the resolution. Each system has different performance so being able to dynamically scale the game’s visual effects across these different platforms is critical as well. Especially when dealing with high pixel density displays, you could actually end up pushing incredibly high resolutions on devices that can’t fully support them. Also you may need to tone down specific special effects on mobile verses desktop or perform special optimizations when going to TV to account for slower display refresh rates. Make sure that you take into account these limitations and plan accordingly.

2. Supporting A Single Control System Across Different Input Types

A single game can support three types of input (mouse + keyboard, controller and touch) based on the device they are on. While thinking through each of these inputs, game designers should consider how their game will work going from desktop to tablet to phone and TV. Will the controls hold up on a system without physical buttons or should the gameplay be simplified a bit to account for the lowest common denominator?

It’s completely possible to have games work with a single input mechanic but a lot of planning and consideration must go into the overall design of the game. Most devices accept a game controller at this point so while not ideal, players can still plug one in if virtual controls are too frustrating. It’s especially important to take into account that not everyone who plays your games will have access to a controller. The Fire TV ships with a remote by default so if you want to capture the largest audience possible you’ll want to make sure you support the remote out of the box. You can still publish a controller only game but keep in mind that each input limitation you place on your game shrinks your potential audience accordingly.

3. Publishing a single game from the same codebase.

For years, developers had leaned on C++ as a cross platform solution to making games that work across multiple platforms. A successful port could be anything above 50% core reusability. I still know developers who build their own game engines that allow them to manually port from platform to platform but that process can be time consuming and if you are a small indie developer, the additional bug testing time may not possible to maintain across all the devices you want to support. That is why it is critical to find a cross publishing solution you feel comfortable with.

The most popular game engine today for indies is Unity 3D. From there other solutions, which grow in complexity, are Unreal Engine, CryEngine. There also some smaller more specialized game engines like GameMaker Studio. If pre-built game frameworks are not your thing, consider some cross compilers like HaXe, Monkey and CocoonJS. Either way there are many options and each will have some kind of impact on your end result or the platforms you can reach so do your research while designing your game.

4. Saving State Across Devices

What good is having a game that can be played on multiple platforms but the player needs to restart their progress every time? A key component to the responsive game design concept is allowing a single game session to extend across different devices allowing your player to start on one platform and continue on another. Imagine being able to play a Fire TV game at home then continuing your game on the go on any mobile device?

Steam was one of the first game publishing platforms to introduce cloud based game saving and since then more companies have offered similar solutions. The biggest issue is that these services are platform specific. For a developer to support different platforms, they would have to roll their own solution. However, built into our GameCircle API is WhisperSync, which can be used to not only have cross platform leaderboards but also sync game data across different mobile devices.

By adding GameCircle’s WhsperSync to your game, you can leverage this to let your players go from mobile (iOS, Android and FireOS) to the Fire TV for the full 10-foot experience then sync their game data back across all of these devices. While GameCircle doesn’t support PC syncing today, being able to have a consistent saved game mechanism for your mobile and Fire TV builds is a huge advantage for your players and a step in the right direction.

Where Do We Go From Here?

While this is just the foundation for a larger concept in game design, it’s up to you as the game designer to help define and shape the future of what gaming on multiple platforms means to the player. At Amazon we are incredibly focused on the customer and we build tools to help you as the developer serve them better. Over the next few years we will see more and more games that reach across platform walls to enable a gamer to pick the device and play style they want and with the correctly designed game, that player will have the same experience no matter where they choose to play your game.

Resources:

• GameCircle https://developer.amazon.com/public/apis/engage/gamecircle
• Amazon Fire TV https://developer.amazon.com/public/solutions/devices/fire-tv
• Publishing to Amazon Appstore https://developer.amazon.com/public/support/submitting-your-app

- Jesse Freeman (@jessefreeman)