Peculiarities of mobile game testing: screen size, touch-interface, resources

For an ordinary user, a video game is a final application that gives him certain gameplay. However, what does a video game mean to a developer?

For a videogame developer, it is a time-consuming process full of inaccuracies that can constantly change throughout the development process. In Jason Schreier's book «Blood, Sweat and Pixels », several points can be identified that lead to uneven development:

1. The interactive nature of games leads developers to the desire to perfectly develop all the details of the game, which in turn takes more of the already limited resources;
2. Technical progress always brings to the development process both positive aspects (new tools, simplification of existing capabilities) and negative aspects (complication of the optimization process, defects due to incompleteness or conflicts of new functions);
3. The quality of the game can only be assessed by playing it, which in turn prevents creating an accurate plan of action.

Mobile game

What is the main difference between a mobile game and a regular video game? To give a comprehensive answer to this question, you need to decompose the game into the following parts:

1. Gameplay
2. Control
3. Graphics
4. Productivity/Performance

Since the mobile platform is limited in resources, it is impossible to ideally cover all four points. When creating complex modern graphics in a mobile game, performance is compromised, while diligently working on detailed gameplay can lead to control issues. Ignoring these features runs the risk of creating a player-unfriendly product.

In general, a mobile game offers significantly fewer opportunities for a team than a project on a PC, which in turn complicates the development process.

Genres and mechanics

Conventionally, the conflict of four points created a certain genre and sub-genre palette. The following genres of mobile games can be named:

1. Platformers
2. Shooters
3. Races
4. Adventure
5. RPG
6. Arcades
7. Board Games
8. Match 3
9. Hidden Object 

Accordingly, there are special mechanics that can be used in mobile games:

1. Touch/Swipe/Multi-Touch – basic control mechanics on mobile devices that lead to similar simple mechanics from the PC industry (click, drag and drop). More often, these mechanics are found in board games, some adapted RPGs, arcades, Match 3 and Hidden object.
2. Virtual Gamepads – These control mechanics are very different from the mechanics of a regular gamepad that you can familiarize yourself with on consoles or PC. Since it is created from separate active elements, with a huge probability the mechanic can conflict with other elements of the interface. In addition, in most implementations, virtual gamepads have extensive customization, which can only increase the risks of creating a defect. This mechanic is universal and can be applied in such genres as RPG, Adventure, Arcade, Racing, Platformers.
3. Mechanics based on gyroscopic sensors. Implementations can be both the usual auto-rotate, which affects the location of interface elements, and a full-fledged aiming assistance mechanic in some shooters.

Features of mobile game testing

Unlike their PC relatives, mobile devices have certain conventions that can influence the quality of the final product in a small or large volume.

The first feature of mobile platforms is the screen size.

Nowadays, there are a huge number of mobile devices with unique screen sizes. If the conventional texture of the model in the game on a device with a small screen of HD resolution will be displayed quite well, then on a large screen of a conventional tablet with FHD resolution, the texture may look mediocre.

This can also include the adaptation of the interface, since most elements are placed with pixel precision, as a result, there is a possibility that on some device objects will be overlapped due to a different resolution.

And after an innovative step from Apple, there are also unique cutouts on the screens, due to which certain elements of the interface can become inaccessible and blocked.

Overlay cutout controls

The second feature of mobile games is gestures, and the Touch interface itself as a whole.

Using the well-known Touch/Swipe/Multi-Touch mechanics, developers get the opportunity to make intuitive and clear controls. But with great opportunity comes great responsibility. Each control element is a separate module that can be broken in the most unexpected ways. For example: the button may not be clickable, or it may be permanently pressed; the scroll animation after a swipe may be displayed in jerks; after pressing several different items repeatedly or simultaneously, you can get a conflict of functions.

Overlay controls

The third feature of mobile games is system malfunction.

This category includes:

1. System gestures:
   • calling the navigation panel;
   • calling the status bar;
   • calling the message panel;
   • physical buttons;
   • рicture in picture;
   • split screen.
2. System interrupts:
   • exit from the program;
   • app minimizing;
   • calls;
   • alarms;
   • enabled music;
   • notifications;
   • low battery.

The application should not crash at any of these points. In the case of out-of-game activities, a pause should be enabled, and the player's progress should be immediately uploaded to the cloud or game servers. After returning to the game, there should be no performance issues and game progress should be the same as before.

The game is cropped in Split Screen mode

The fourth feature of mobile games is the quality of the mobile Internet.

It is important to understand that mobile devices have two main types of connection to access the Internet: WiFi and Mobile Data (Edge, 2G, 3G, 4G, etc.). Analyzing each type of connection, you can come to the conclusion that the principle of operation is quite similar. In fact, the quality and reliability of the network fully depends on the coverage and load, as a result, it is necessary to test both good and worst scenarios. For example, after a successful transaction, the user may not receive the desired content due to the fact that the work with the server was unstable, although according to the documentation, the application should not create such cases. Or, for example, the function of the program becomes unavailable due to a disconnection with the server with good network quality.

Unstable connection

The fifth feature is productivity. The most important, but sometimes ignored by developers until the final stages of development, point. This includes the speed of launching game locations, frame rate during idle scenes, frame rate during loaded scenes, and frame rate in complex locations.

The optimization process is not always easy and certainly cannot be implemented quickly.

In order to dig deeper into the complexity of the optimization process, one can inquire about the experience of CD Project Red and their legendary porting of The Witcher 3 to the Nintendo Switch platform. The team spent an entire year reworking many aspects so that the best game of 2015 without gameplay cuts could make the transition to the mobile platform. Article on IGN. 

Performance testing can be done using specially written location benchmarks, or measurements can be made manually. For frame rate measurements in mobile games, the built-in functionality of the engine is used, or various FPS monitor applications that require detailed settings. The frame rate unit is FPS (Frame Per Second).

Mobile game testing requirements

The device to be tested on should be factory reset to make sure it doesn't conflict with pre-installed apps.

If the mobile game has the function of interacting with other applications, the installation of these applications is allowed, because this test complies with the end-to-end standards.

Points to be checked:

1. Build structure:
   • in the structure of the build there are icons for all current or declared in the specification screen permissions;
   • the SDK version with which the mobile game was built matches the SDK version of the maximum supported device.
2. During the first launch, be sure to check:
   • Landing Page – a page after launching the program, which displays suggestions from the developer;
   • Splash Screen – the image that appears when the game is loaded, most often the logo of the developer's studio or the publisher;
   • Loading screen – loading screen, which displays mostly thematic art with a progress bar (sometimes developers add game hints to this component).
3. After downloading the application, check:
   • menu;
   • profile;
   • settings;
   • support;
   • information about the publisher.
4. Inside the game we check:
   • sound reproduction correctness;
   • game mechanics;
   • save game
5. In the case of the presence of the function of binding social networks and other third-party services, it is mandatory to check the binding to each service.

Examples of bugs

The car fell under the textures. GTA SA

The car got stuck in a tree. PUBG Mobile

The player fell under the textures. PUBG Mobile

Game testing is a complex, but nevertheless interesting process that requires high-quality preparation before carrying out. We hope that this article has helped you understand the many points and specifics associated with this area of testing.