There are a lot of unsuccessful mobile games that didn’t make it to the top because they presented UX issues in their game mechanics and playability. But what about the successful ones? Can a top ranked game like Sky: Children of Light be successful and still have UX issues?

In this article we are going to find that out using the Hannu Korhonen and Elina M.I. Koivisto Playability heuristics as the main tool for the UX analysis.

Game Overview

I chose Sky: Children of Light as the subject of the UX analysis because I wanted to test a high ranked game. Sky was the 2019 Game of the Year in 2019. This was a motivation to put the game up to a challenge. 

Sky: Children of Light was developed and published by Thatgamecompany. It’s a beautiful multiplayer adventure mobile game with strong social features as a core part of its gameplay. It’s stunning art and fluid design makes you feel like you’re playing the sequel of “Journey”. 

The gameplay consists in traveling to different worlds with a special cape that grants the user the ability to fly for a period of time. As the game progresses the player has the ability to upgrade the cape and increase their flying time. While flying through different worlds the player can release spirit memories that will give them social gestures as rewards to interact with other players.

UX Analysis 

For the UX analysis I’m going to use the Playability Heuristics. This method focuses on three main areas: Game Usability, Game Mobility and Gameplay.

Game Usability

The game usability covers the game controls and interface through which the player interacts with the game.

Game Mobility

Game mobility evaluates if the game easily allows a player to enter the game world and how it behaves in diverse and unexpected environments.


The Gameplay evaluates the platform on which the game is played, as well as the mechanics and all the possible interactions the player has with the game world.

To successfully evaluate a game using heuristics it’s recommended to have some knowledge of the gameplay and the interface of the game. 

For that reason I played the game for a week to experience and test it in different scenarios.

UX Findings

The results of this analysis are based on whether the principles of the heuristic were satisfied in each of the aforementioned sections (Game Usability, Mobility, and Gameplay ). 
The game scored a total of 62.07% out of 100% in the playability heuristic. I found most of the issues in the Gameplay section with 7/14 failed principles, followed by Game Usability with 3/12

Game Usability

The score for Game Usability was 70.45%. The most important issues that failed the principles heuristics are as follows,

1.- Navigation is consistent and minimalist.

Problem Description

Navigation is hard to find and does not have the right affordance to hint the user where to go. In order to return to the home hub, the player needs to click on the icon on the center of the screen which represents an entirely different thing than a navigation menu (cape energy/power bars ).

After tapping on the icon, a menu appears showing gesture icons that the player unlocks in the game. In the gesture menu the player will find an icon in the shape of a gate that will allow it to return to where they started. 

The elements of the navigation are not structured based on related items, rather it shows all the information at once which makes it hard to understand.

The player cannot navigate to the settings menu at will. The settings menu appears when the game thinks you need it, sometimes it just appears in the right upper corner but the player doesn’t have much control over it.


The navigation could be structured by different sections e.g Settings, Gestures, Home, worlds, etc. Each of the sections could have a brief explanation of what the player can do on each of them. 

These solutions will help the user identify relevant information easily and fast. The navigation should be visible at all times with the ability to be collapsable to minimize distractions when playing.

2. Game controls are convenient and flexible

Problem Description

Controls are not ergonomic, and they are really hard to use in an iPad device. The way the player controls the character in the game is based on a set of standardized controls ( movement and camera controls ) plus gestures to make the character perform specific actions, like running faster.

The issue with the controls comes when the player tries to combine them, making them hard to use. The controls require a lot of hand movement.

The game allows you to change the controls ( if you find where to change them) to a more conventional and easy approach but still some actions still require the use of gestures.


Control settings should be easy to find. An alternative option for the player could be to have an easy access button to change from the different types of control so they can switch back fast for different scenarios.

The sensitivity of the controls could be improved to allow for a more accurate control of the character.


The score for the gameplay part of the heuristic was 72.32%.

Having the most important issues that failed the principles heuristics are the following:

1. The game does not stagnate

Problem Description

After many hours, the game feels like you are doing the same thing over, and over again. There is no real challenge in exploring the worlds, giving it a feeling of little to no progress. The only thing that changes is the improvement of the flying ability and the expressions.

The feeling of not seeing progress is increased by the scarce information the player gets from the different features in the game: Expressions System, Friend System and Season Pass.


Once the player clears the first or second world, the game could give them information of how the game features work in detail so they can start progressing in those as well. Each of the worlds could have different levels of difficulty as you progress in the game, allowing the player to discover new spirits or secrets.

2. The player does not lose any hard-won possessions

Problem Description

One of the most valuable possessions the player has in the game is the item to increase the flight ability. The player gets those items through exploring different worlds.

At the beginning of the game it is not clear enough that the players could permanently lose the flying boost items that they collected. A hint by the world is made when the different worlds start to change the weather (rain or water environments) that make the character lose his life or stamina to the point where the item somehow is removed and thrown away from you. In some cases this happens too fast while flying, making it really hard to understand what just happened.

The player can recover the item if he goes back for it. But If by any chance they miss it, there is no clear hint that you can recover it later or that it will remain where it fell.

The same issue applies to a special area of the world, where the game informs the player that by entering the following area there is a chance of losing some items. Though again, it’s not clear if the player could recover those at some point, or if they have to start all over again.


The game could be clearer in the onboarding tutorial. It could warn you that you lose health, stamina or your items in different scenarios. An animation highlighting the items could help visualize it better. If there is a chance to lose the item the game could implement a visible timer notifying and guiding the player to recover it.

3. The game provides clear goals or supports player-created goals

Problem Description

At the beginning of the game the story hints to the player that they need to go to the top of a mountain. After the scene has played, the player can then roam the different kingdoms freely with no clue or sense of progression towards the assumed final goal: going to the mountain.

The player throughout the game has different things to do ( like freeing spirits, using and upgrading expressions, making friends, and upgrading or buying custom clothing). None of the mentioned activities help the player reach the mountain. 


The game could be less ambiguous on what is the main course the player has to take to finish the game. As well as to provide them with relevant information little by little depending on which stage of the game the player is. Clear instructions on how to complete quests, how to upgrade (and the benefits of doing so) could really help the player achieve the goals easier.


Game Highlights

  1. The game has an outstanding audio-visual presentation that supports the gameplay
  2. The game screen layout is efficient and visually pleasing
  3. The first-time experience in the game is encouraging
  4. The game story supports the gameplay and is meaningful

Game Opportunity Areas

  1. Indicators are visible
  2. Navigation is consistent and minimalist
  3. Game controls are convenient and flexible
  4. The game provides clear goals or supports player created goals
  5. The game does not stagnate
  6. The player does not lose any hard-won possessions

Having finished the UX analysis of the game we can now go back and answer the following question: Can a top ranked game like Sky: Children of Light be successful and still have UX issues? 

Sky: Children of Light has a good experience overall. The game had a score of 72.32% total in the playability heuristic with just a few critical issues. 

The game covers the majority of UX standards and provides a good experience to players. Based on the Heuristics and my time playing the game, there are  some areas of opportunities that definitely could improve the overall experience. This however doesn’t have a negative impact on the core experience of the game.

A high number of critical UX issues in most games will create a negative experience that will make players eventually abandon the game. That’s not the case for Sky: Children of Light. It’s great art, music, and fluid animation makes up for the several issues found with the playability heuristic.
If you have any question regarding the ux analysis feel free to send me a message at I’ll be more than happy to answer.