Build great games

Great games on Google Assistant smart displays combine immersive visuals and a well-designed spoken interface. Blending conversational design best practices with game graphics and touch interaction is key to building a gaming experience that will keep your players coming back for more.

Learn about the most important practices for creating a successful game on Google Assistant devices.

Design with a focus on visuals

This game for kids uses visual instructions and tappable suggestion cards.

Graphics are an essential component of games on smart displays. When targeting these devices, start your design process with a focus on visuals and game flow, using techniques such as storyboarding. Blend in the conversation to complete the experience.

Strong visuals help players stay engaged and follow the action as they interact with your game. It's easy for players to miss a verbal cue because of distractions or in a noisy environment, so providing visual prompts as well as voice prompts helps keep the game moving.

Apply voice interface rules

Building a great voice interface for your game requires anticipation of your players' needs. Voice-forward games are relatively new, so players may not know what they can say, when they can say it, or how they can say it. Players can-- and will--say anything, and your game should be able to handle it. Follow these voice interface best practices to guide your conversational design:

Be a consistent guide: Players can easily get lost in the unfamiliar territory of conversational interfaces, so plan to set expectations for how your game works up front. As game play progresses, it's important to be ready to step in and help them find a path forward:

• Plan on providing a brief onboarding tutorial for the verbal interface at the start of your game.
• Re-prompt the player when your game has not received input for 10 seconds or more.
• Re-prompt the player when your game does not understand what the player said.
• Provide prompts or hints tailored to different sections of your game.

Be ready for anything: With voice interfaces, players can say anything at any time and expect something to happen. This expectation is very different from other game platforms, where inputs are limited to finger controls or gestures:

• Allow users to ask for help, repeat instructions, or pause at any time.
• Plan to handle anything players throw at your game, from frustrated outbursts to victory cheers. This approach makes for a more immersive experience, but be careful not to overdesign. For more information, see Design for the long tail in the Conversation design site.

For more information, see the Conversation design website.

Use voice hosts and characters

The cookie character uses an animated voice that's suitable for kids.

Players naturally associate spoken words from your game with a character or persona. Change the speaking voice of your game and your players will immediately notice and assume they are interacting with a new persona or different part of your game. Here are a few key considerations in designing game personas:

• Design for consistency: Players are highly sensitive to changes in spoken voices and small changes to voice can be distracting. Using a generated voice can help make your game development go faster, make updates easier, and provide a better user experience. You can check out Google Cloud Text-to-Speech for various smart home speaker voices that can be used with SSML in your game. The game host for Mime Jam uses an Australian voice generated by Cloud Text-to-Speech:
  
  Note: Even when using a generated voice, you should also consider the consistency of verbal style and use of language, as this is also noticeable to players.
• Design a host persona: Consider designing a host persona to help your team provide a consistent game experience. A host persona creates a valuable anchor point for players to follow along and get help. For example, the following audio clip demonstrates the narrator at the start of Gnome Garden:
  
• Design for recognition: While players can notice small differences in spoken voices, you should design your characters to be distinct and engaging from an audio perspective. A distinct voice for prompts lets players know that the game is running and expecting input, even if the character is not on screen or if the player looked away.

For more information on using personas as part of a voice interface, see the Conversation design website.

Test continuously

Constantly test your game as you're developing. Test every aspect of your game, including basic functionalities to ensure the ease and flow of conversations, placement and sizes of visuals, and other game elements. Conduct these tests on both the device simulator and physical devices. Follow these testing practices while developing your game:

• Test the conversation on-device: What you write on a page may sound different when spoken by a device. This technique can help you catch repeated words, long sentences, and clunky or awkward phrasing.
• Test the conversation with other people: What people say in conversation is unpredictable. To help figure out what players may say to your game, test conversations from your game with other people to see what kind of responses they provide.
• Test your graphics with devices: Graphics viewed and tested on a computer screen may look different on smart displays.
• Test on various devices: Smart displays come in different sizes. If possible, test on several kinds of devices to ensure optimal screen resolution and game performance.

If you're developing a game that is available in multiple languages, do the following:

• Test each language separately: Each language can have its own pronunciation and speech recognition issues, so be sure to test the conversation on-device and test the conversation with other people for each language.

Even after initial development, you should continue to test your game, look for improvement opportunities, and update your Action as needed.

For more information about testing conversational designs, see the Conversational design site.

Consider game types

Many types of games can be successful on Google Assistant. Here are a few types of games that work well on the platform:

Turn-based: Games that use a simple prompt and response mechanic, such as:

• Open ended conversations, such as question and answer interactions
• Option selection, such as trivia without timer constraints

Example game: Cookie Detective

Rounds in the Mime Jam game are one minute each.

Real-time: Games that use time limits and quick interaction to drive gameplay, such as:

• Word guessing or word scramble games
• Puzzle games
• Timed trivia

Example game: Mime Jam

Note that this game type can benefit from using Continuous Match Mode.

Idle: Games that operate in the background while the player is not playing:

• Farming games
• City building games
• Empire building

Example game: Gnome Garden

Build with touch interaction

When building games for smart displays with Google Assistant, use touch screen functions as a supplement to the voice interface:

• Voice and touch parity: Ensure that everything players can do by touching the screen they can also do with their voice, and vice-versa. Players should be able to alternate between touch and voice seamlessly. They may not be able to reach the screen during play, and similarly, may miss spoken cues and need to refer to the screen for hints.

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  The Cookie Detective game uses touch to select a hiding spot.

  Touch as a supplement to voice: Provide touch inputs as an alternative way to complete an action or hints about how to proceed. For example, touch screen inputs can be available on screen for players' responses, even after a long pause in the game conversation. In some cases, touch interactions can be a faster way for players to respond to game activity than voice input.
• Touch as a complement to voice: Use touch inputs with voice to create useful interactions. For example, allow players to touch the screen and hear spoken information about game objects.

Drive player visits and replay

Bringing folks back to your game on Google Assistant regularly is just as important as any other game you build. While starting a game with a voice interface is quick and simple, players need to know the right words and be motivated to play again. For this reason, your game design should include a strong focus on re-engagement:

• Engaging game play: The best way to keep players coming back is to make sure your game is fun. Give your players an experience they want to repeat.
• Accelerated re-engagement: Focus on getting returning players to where they left off quickly and acknowledge their return: "Hey Player! Welcome back!" Use features like Home storage to save game states for multiple players and get them back into play quickly.

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  Use the Home storage feature to save high scores for returning players.

  Reminders, notifications and routines: When players exit the game, remind them how they can return: "If you want to play again, just say…" Offer to set up notifications or a Google Assistant Routine to automatically remind players to return for bonuses. For more information, see User Engagement.
• Leaderboards and other tools: Don't forget to use replay techniques that work in other games, like timed events and leaderboards.