DECISION-MAKING ON GAME ENGINE FOR HYPER-CASUAL GAME DESIGNING

Taras Voloshko, Tetiana Shestakevych, Lviv Polytechnic National University, Lviv, Ukraine

Abstract – Hyper-casual games gained popularity with a simple plot and easy interaction. Developers should consider the short life of such a game, so they use game engines, which help build the basis of the game. Choosing the most relevant engine is an actual and interesting task, and the analytical hierarchy process seemed to be suitable as a self-proven method of decision-making support.

Keywords: Hyper-casual game, analytic hierarchy process, AHP, game engine.

Introduction

On understanding the possibilities of information technology as a gaming platform, the development of computer games has become an industry with many directions, fans, and ultimately eSports competitions [1]. A notable representative of the currently popular genre is a hyper-casual game, which has gained popularity in recent years. They have almost no plot, and they are fast games that often take up to a minute. Hyper-casual games require almost no instructions and take up little resources in the smartphone. An interesting and urgent task is to develop a hyper-casual game and implement in it the key characteristics inherent in popular games of this genre.

Hyper-casual games on mobile platforms

Hyper-casual games are a relatively new game genre with simplified controls or minimized player involvement [2]. Usually, such a game has a minimalist design and does not require long interaction with the game, in a game of this genre the player uses only one button or even special capabilities of the smartphone, for example, the position in space or the speed of movement of the device. The goal of the game of this genre is mostly simple and does not require the player to spend a long time in the game. An example of a popular hyper-casual game is Hide and seek cat escape (Fig. 1).

Fig. 1. Screens of the game Hide and seek cat escape (audience >10 000 000)

One of the most significant challenges facing developers and owners of hyper-casual games is the length of the game’s lifecycle. A peculiarity is also that the player, having reached a certain level of player skill, loses interest in the game. Researchers [3] proposed the concept of personalizing the difficulty levels of a hypercasual game to keep the player’s attention.

Tools of game design

The popularity of hypercasual games among developers is influenced by the ability to use various free and paid game engines. Let’s analyze the available game engines and select one that meets the requirements set earlier.

Game engines are reusable components that developers use to build the foundation of a game. There are dozens of different engines for video game development, each with advantages and disadvantages: being used exclusively for mobile platforms using 2D graphics, being used for developing browser games, and more. Unity, Unreal Engine, GameMaker, Godot, etc. are popular among game engines. Despite the similarity of the basic functionality, such engines have certain differences, which can be decisive in the choice of an engine for the implementation of a hyper-casual game. Let’s consider the features of the indicated engines.

Unity is a cross-platform game engine that allows one to easily create interactive 2D and 3D content [4]. The main programming language is C#, which has a medium entry threshold, a large community of like-minded people, and open documentation, which makes it easy to find the desired function or method. Unity supports the screen extension of all smartphones and all operating systems of mobile devices.

Unreal Engine is a game engine developed by Epic Games [5]. The programming language is C++. Updates to the latest version of the game engine [6] occur almost every month. The advantages of Unreal Engine are a high-quality tool for working with various types of graphics, as well as an improved system of Blueprints, which will help in working through a visual interface without the critical need for in-depth knowledge of the C++ programming language. Disadvantages include the need for a licensed copy to work, the need to pay a percentage of the profits from the developed game after it becomes profitable, and the need to have a development team.

GameMaker is a cross-platform design engine for creating 2D games. The engine has a simple and clear interface, comprehensive documentation, video tutorials, and forums about its operation and game creation [7]. The GameMaker Studio editor allows the creation of not only 2D games but also using 3D graphics [8]. The engine allows you to create 2D games using your graphic objects, sounds, and animations, which can also be created and edited in GameMaker Studio. Unlike most other game engines, GameMaker Studio does not require programming skills. Users can “pick and click” to create a game, which is easier and faster than coding. However, this limits the functionality of the available elements. Wider functions of GameMaker require the use of a paid version of the engine.

Godot is an open-source, multi-platform 2D and 3D game engine licensed under the MIT [9]. An engine offers a significant set of common tools and is open source, that is, there are no royalties, subscriptions, hidden payments, etc. Godot has a community that is constantly fixing bugs in the engine and developing new features.

Engine selection

Let’s evaluate the engines mentioned above according to the characteristics that are important for the development of hyper-casual games. To achieve the general goal of developing a game project (hyper-casual game), it is important to achieve two goals: minimizing development costs and reducing project development time. To decide about the best game engine, we shall use the analytic hierarchy process, AHP [10]. To start, we will compare alternative game engines according to the specified criteria, which are correlated with the main goal.

Let С = {C_i | i=1,…, 4} be a set of 4 criteria:

No royalties (С₁).
Low entry threshold (С₂).
The presence of visual programming technology (С₃).
Availability of 3D graphics (С₄).

Let Т = {T_j | j=1,…, 4} be a set of alternative game engines that can be used to develop a game:

Unity (Т₁).
Unreal Engine (Т₂).
GameMaker (Т₃).
Godot (Т₄).

The hierarchy of decisions is shown in Fig. 2.

Fig. 2. Hierarchy of decisions in the analytic hierarchy process regarding the expert evaluation of game engines

To evaluate alternatives, we compare every two alternatives considering each criterion. Based on the expert assessment, a matrix of pairwise comparisons is formed. Then A is a 4х4 matrix of paired comparisons, A=(a_ij), where a_ij> 0, a_ji> 1/ a_ij, a_ii= 1, where i = 1,…, 4, j = 1,…,4, where a_ij is the ratio of the importance of one alternative over another (for example, in Fig. 3 it is shown the matrix of expert judgments regarding the criterion “Availability of visual programming technology”).

Fig. 3. Comparison matrix by the criterion “Availability of visual programming technology”

Four matrices of pairwise comparisons are formed from the evaluations according to four criteria. For each matrix, a corresponding normalized one is constructed, the sum of the elements of each row is divided by 4, and the resulting vector is a local priority vector (Fig. 4). Also, fig. 4 shows the calculations necessary to determine the consistency of experts’ opinions, i.e. the value of L. To find it, the elements of each column of matrix A should be summed, and L can be obtained by multiplying the found vector of sums by w. To find the CI consistency index, L should be reduced by the number of alternatives and divided by the number of alternatives-1. The consistency ratio CR uses the random consistency index RI (Table 1) CR=CI/RI. A consistency coefficient of less than 0.1 indicates that the matrix meets consistency standards (Fig. 4).

M	1	2	3	4	5	6	7	8	9
RI	0	0	0.58	0.9	1.12	1.24	1.32	1.41	1.45

Table 1. Random consistency index (M is the dimension of matrix A)

Priority vectors are summarized in Table 2. Each of the criteria will be considered equally important.

Table 2. Comparison of the characteristics of game engines

	С₁	С₂	С₃	С₄	Relative priority
Т₁	0,334	0,332	0,320	0,336	0,331
Т₂	0,133	0,291	0,074	0,346	0,211
Т₃	0,459	0,291	0,320	0,096	0,291
Т₄	0,073	0,086	0,285	0,223	0,167

Fig. 4. Calculations in the method of analysis of hierarchies

The relative priority vector contains the overall rating of the alternatives (calculated as the average for each alternative). The alternative corresponding to the largest value is the best. According to the vector of relative priority (table 2), the most relevant game engine is Unity. Therefore, the further development of this engine will be used to develop a hyper-casual game.

Conclusions

Based on the features of hyper-casual games, various game engines were considered and analyzed. Using the decision-making method, the best engine turned out to be Unity. Using it, hyper-casual games will be developed, and it is additionally possible to use Figma, MagicaVoxel, Photoshop, etc. environments. To implement the game, one should choose 3D graphics, this characteristic of a hyper-casual game is a relevant criterion for the success of a hyper-casual game. To evaluate the success of the implemented game, it is advisable to use APi FacebookAds and GameAnalytics. These APis collect data on the number of users attracted by advertising, time spent in the game, and user churn.