Inside Spirit of the Island’s cross-platform mobile port

In 2020, 1M Bits Horde and META Publishing entered into a partnership to develop Spirit of the Island. The title, a simulation game where players are responsible for restoring the island into a tourist attraction, was released on PC in 2022 and on consoles in 2023. Over the past year, with help from game development studio Brave Zebra, the teams have shipped the game on mobile. They have also added a cross-platform, two-player co-op feature.

We interviewed Axel Garcia, studio head at Brave Zebra, and Ilya Grabelnikov, chief publishing officer at META Publishing, to learn how they overcame hurdles while porting to mobile and implementing cross-platform functionality.

How would you describe Spirit of the Island?

Ilya Grabelnikov: Spirit of the Island is a beautiful SIM sandbox role-playing game with cross-platform online co-op possibilities. Set on a tropical archipelago, players can build their farm, grow crops and animals, craft various items, cook dishes, gather resources, build shops and a museum to attract visitors, and turn a desolate Island into a prosperous tourist destination.

From the outset, was the plan to always launch on multiple platforms?

Ilya: When the game was in the prototyping stage, it was solely a single-player experience. After analyzing the market trends and needs in 2021, we felt that players would enjoy it as a platform-agonistic co-op game.

This was challenging since there wasn’t another similar title on the market, so we didn’t have a reference point. We weren’t able to predict the potential challenges. There were a number of great games, but all of them were either single-player or single-platform co-ops.

We decided that it was the right time to start developing a multiplatform title with a cross-platform play feature. The platform order was defined based on the origin of the production: PC, then consoles, and then mobile.

What has been unique about porting to mobile compared to other platforms?

Axel Garcia: Porting Spirit of the Island to mobile involved several substantial technical and design adjustments due to the platform’s unique characteristics. The game blends complex menu-driven management, navigation, and real-time 3D interaction, which required us to make UX design decisions tailored to each platform.

Mobile users play on smaller, high-density screens using touch input, unlike PC users (mouse and keyboard) or console players (gamepad from a distance). This meant that we had to completely rethink how players interact with the game on mobile, both visually and functionally.

How did the team solve this?

Axel: To adapt, we enlarged UI elements and fonts for better readability and interaction on mobile. We also built a responsive and scalable layout system using Unity’s Canvas Scaler, Anchors, and layout groups to dynamically adapt to different screen sizes and aspect ratios.

Designing a context-aware on-screen control scheme, with buttons that change based on player activity (exploring, fighting, building, etc.), was key. We implemented a drag-and-drop mechanic, enabling intuitive item management and crafting interactions via touch gestures.

We also used Unity Remote to quickly test UI placement, button feedback, and text scaling in real time on actual devices, which dramatically improved iteration time. This was particularly useful for tuning touch areas and contextual button behavior.

Game asset optimization was also a must. Mobile devices have tighter performance budgets, especially across a range of Android hardware. To ensure the game runs smoothly, we optimized textures, particle systems, and level terrains, and preserved visual quality while reducing resource usage to fit within mobile constraints.

To reduce the Android Package Kit (APK) file size to meet Google Play store requirements and improve download performance, we split the game’s content. We implemented Unity’s Addressable Asset System so that only the main menu is included in the APK. After launch, it dynamically downloads the remaining game content from a server-hosted solution. This setup reduced initial download size and ensured compliance with platform policies.

What was the biggest technical challenge while implementing cross-platform play?

Axel: The biggest technical issue was sync and online co-op delivery. Mobile networks are limited in their speed, so we had to ensure that players didn’t feel the delay. For example, a game requires a minimum of 5 MB/s to be playable without a delay. This is a challenge.

Network package size must also be considered for syncing the gameplay. It cannot be lower than 350KB to ensure stability. Since the game has thousands of objects, such a limit is a big challenge.

How did the team avoid a potential sync delay?

Axel: We modified the Photon-based multiplayer system to support content streaming via Addressables on Android. Multiplayer scenes and assets were structured to load dynamically without breaking matchmaking or session integrity. This helped with hosting and joining multiplayer sessions from Android devices as seamlessly as on PC or consoles.

In addition to supporting cross-play, what other quality improvements were shipped towards the end of last year?

Ilya: We have released a big pack of Quality of Life (QoL) updates. We have improved the UI and the interactions with the objects within the game, and added the Strategy Guide that discloses a lot of the items that are available for crafting and production. Since the game is now cross-play, the challenge is to keep all platforms consistently updated. As a solution, we fixed some bugs that can run on all platforms.

What can players expect from your next game update?

Ilya: We are fixing bugs and achievements. We are including items we promised the community: a new guide map, some quest bug fixes, and new decoration objects. We are also making performance improvements over the two available islands for players to build their paradise. We hope our community is happy and enjoys these updates.

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