Design Guidance for Building Short Loop Mobile Worlds

Introduction

The following are best practices and design considerations to consider when building mobile worlds on Horizon. 

Duration

The average mobile gaming session tends to be short (3-5 minutes), so shorter game loops that are progressible within that time may be more attractive to play. The option to make progress quickly lowers barriers to initiating sessions in mobile games and virtual worlds. 

Examples of ways to do this include:

  • Giving a short block of time in which an action can be completed
  • Using a timer or a countdown clock to create structure and a sense of urgency
  • Providing short challenges, such as a dress up challenge or running through an obstacle course
  • Including mini games (like trivia) 
  • Play with repeatable fun, where future iterations can allow the player to get a different result (like getting a fortune read by a fortune teller)

Design Considerations

Visibility
While in VR a dimly lit environment has been reported to be appealing, darker games/experiences may be harder to see on a small screen. Written instructions, leaderboards, and object prices may also be difficult to read on a smaller screen. Music Valley and Soapstone are examples of worlds that use calming but contrasting colors that are easy to see on mobile. For mobile, consider:

  • Using contrasting colors that are easy to view on a smaller 2D screen. 
  • Avoid signage with lots of words. 
  • Consider creative options for conveying instructions and leaderboards.

Audio
While 3D dynamic audio is important for an immersive VR environment, mobile game audio should focus more on clarity. Mobile may join using headphones or even the built-in speakers on their mobile device. Both forms have less sophisticated outputs than those found in VR headsets or high-end gaming PCs. This means that audio designers need to optimize their sound effects and music to sound good on a wider range of devices with varying speaker quality. For mobile, consider:

  • Ensuring high audio quality so that players can hear what is going on in the world with headphones while they are on the go. 
  • Adding or highlighting multiple audio options to allow players to tune out distractions in a world (such as other rowdy users). 

UI & Controls
Designing the user interface (UI) for mobile games is different from VR due to limited screen size, touch input, and player preferences. While in VR certain actions may feel more intuitive, the UI for mobile games needs to quickly communicate to players how to easily interact within the world. For mobile, consider:

  • Giving players an option to adjust the layout of inputs (or a few layouts to choose from).
  • Ensure that the icons used for buttons clearly communicate the intended action. 

Game Mechanics
Mobile players often are looking for a shorter gameplay experience and games have limited controls due to screen size. Therefore, straightforward game mechanics work best for mobile games. Mobile users can’t duck or raise their hands like users can in VR, so finding unique ways for them to participate as embodied avatars is key. Interacting with objects can also be difficult, so if items are placed within a world ensure that mobile players can easily engage with them. For mobile, consider:

  • Straightforward but engaging core loops (progressable within 3-5 minutes, see Duration section above)
  • Gameplay that hinges more on social fun and does not rely on dexterity or specific avatar movements for the game to be satisfying.
  • Where certain avatar movements are not possible, include a mobile workaround (like the rocket jump button in Citadel). 

Communication
Mobile users may be joining from a variety of locations - both public and private. Therefore, their willingness and ability to communicate verbally may also vary. Verbal communication is a great way to promote socialization and relatedness, but is not required for meaningful player interaction. For mobile, consider:

  • Providing nonverbal ways for players to interact, express themselves, and communicate, which may help players feel they can express themselves even when they can’t participate verbally.
    For example:
    • Custom emotes
    • Custom avatar animations 
    • Releasing a balloon, pushing a button, or triggering another in-world object
    • Providing wearables to signify different statuses
    • Including ways to show if players are open to others joining mini games

Use Cases

Multitasking
Mixing play in virtual worlds with other activities is common on mobile. While VR users are typically immersed and fully focused on the experience at hand, mobile users may jump on for a more casual and flexible experience while doing other activities, like watching TV, eating dinner, or doing chores.Taking this into account, consider building worlds that allow for a “spectator mode” and allow more flexibility for stopping and restarting as needed. 

On-the-Go Gaming
Mobile devices are often always with us, making them a convenient option for quick gaming sessions. Users can easily access their games and start playing within seconds no matter where they are. This differs from VR sessions, which typically take place in the home. Building worlds that are suitable for on-the-go play means considering games that can be played with one hand, making sure they make sense with the sound off if headphones are not available, and being able to pause and start again as needed. 

Connecting with Others
Today, many players join mobile as a way to extend social interactions that will start or continue in VR or as a way to connect with friends who are playing in VR. As Horizon Worlds is now accessible to everyone with a mobile phone, we may see individuals using this as a more-fun-than-a-phone-call way to catch up with friends and family.