Creating a clicker on Unity for Android: a step-by-step guide

Mobile game development is an exciting process that opens the door to the world of digital creativity and potential earnings. Among the many genres, clicker games, or idle gamess, occupy a special place due to the simplicity of the mechanics and high audience involvement. Even a novice developer can create such a project on the engine Unity for the platform Android if he consistently understands the basic principles of the engine.

In this article we will analyze in detail the entire path from creating an empty project to assembly ready .apk file that can be installed on a smartphone. You will learn how to set up the scene, implement resource accumulation logic, save the player's progress and adapt the interface to different screens of mobile devices. The main thing is not to be afraid to experiment with the code and engine settings.

⚠️ Attention: The Unity interface and Android SDK settings may vary slightly depending on the version of the engine and the operating system of your computer. Always check the official documentation if difficulties arise.

Preparing the environment and setting up the project

The first step is to install the necessary software. You will need the engine itself Unity Hub and the selected version of the editor Unity. For Android development it is also critical to install Android Build Support along with Android SDK and NDK via Unity installation modules. Without these components, compiling the project for the mobile platform will be impossible.

After installation, create a new 2D project. In the project creation window, select a template 2D Core, since clickers usually do not require complex 3D calculations, which will have a positive effect on performance on weak devices. Name the project, for example SuperClicker, and specify the path to the folder without spaces and Cyrillic to avoid compilation errors.

Immediately after creating the project, you need to configure the build parameters. Go to the menu File → Build Settings and switch the platform from PC, Mac & Linux Standalone to Androidby pressing the Switch Platformbutton. This process may take several minutes, as the engine recompiles internal libraries for the new ARM processor architecture.

In the same build settings window, go to section Player Settings. Here you need to set a unique package name in the Package Namefield, for example, com.yourname.superclicker. Also install the minimum API version (Minimum API Level) not lower than Android 7.0 (API Level 24) to cover most modern devices, but weed out completely outdated models.

User interface (UI) design

The heart of any clicker is its interface. The player will spend most of their time looking at buttons and numbers. To create a UI in Unity, the system is used Canvas. Create it through the menu GameObject → UI → Canvas. In the Canvas Object Inspector, set the Mode Canvas Scaler to Scale With Screen Size, specifying the Resolution 1920×1080. This ensures that interface elements will scale correctly on screens of different sizes.

The main element of interaction will be the button. Add an object UI → Button - TextMeshPro (or just Button in older versions). Place it in the center of the screen. In the Image button component you can set a sprite, and in the child Text object you can change the label to “Click!”. It is important to customize the colors of the button states (Color Block) so that when pressed it reacts visually, for example, becoming darker.

You will also need text fields to display the current score and the cost of improvements. Create several objects UI → Text - TextMeshPro. Place one large text at the top of the screen to display coins, and others near the buttons for purchasing upgrades. Don't forget to link the fonts TextMeshPro, otherwise you will see squares instead of text.

• 🖱️ The click button should be large enough for easy pressing with your finger.
• 💰 The invoice text should be well readable and contrasting.
• ⚙️ It is better to place the settings menu in a separate panel or modal window.

Writing game logic in C#

Now let's move on to the actual the interesting part is programming. Create a folder Scripts and inside it a new C# script called GameManager. This script will be responsible for storing data and processing clicks. Open the script in a code editor (for example Visual Studio or Rider).

Inside the class GameManager declare public variables to store the number of coins and click strength. Use type long or double instead int, since in clickers the numbers can grow to very large values, exceeding the limit of the integer type. Also create a link to the UI text field to update the displayed score.

public class GameManager: MonoBehaviour
{
public long coins = 0;
public int clickPower = 1;
public TMPro.TextMeshProUGUI coinsText;

public void OnClick
{
coins += clickPower;
UpdateUI;
}

void UpdateUI
{
coinsText.text = coins.ToString;
}
}

After writing the code, return to Unity. Drag the script GameManager to an empty object on the stage (create GameObject → Create Empty and name it "GameManager"). In the inspector of this object you will see fields to fill. Drag the object with the text of coins from the hierarchy into the field Coins Text script.

⚠️ Attention: Never change the values ​​of variables directly in the code while the game is running for testing. Use the inspector or console commands so as not to break the logic of saving progress.

It remains to associate the button on the screen with the click method. Select the button object in the hierarchy, find the component Button in the inspector and in the section On Click click plus. Drag the "GameManager" object into the field that appears, select GameManager → OnClickfrom the drop-down list. Now, when you click on a button in the editor (in Play mode), the score should increase.

Upgrade system and store

Any The clicker becomes boring without the ability to progress. We are implementing a simple system for purchasing upgrades. Create a new script UpgradeManager. It needs to store the cost of the improvement and the function of purchasing it. The logic is simple: if the player has enough coins, we subtract the cost, increase the click strength and increase the price of the next upgrade.

Usually the price increases exponentially. The formula might look like this: new_price = current_price * 1.5. This balances the game by making each upgrade more difficult to acquire. Create an improvement button prefab that will contain the name, price and the buy button itself.

To dynamically create store buttons, use the Instantiatemethod. You will need a list of enhancement data, which can be stored in a separate class or ScriptableObject. When the game starts, the loop goes through the list and creates the corresponding buttons in the store panel, linking current prices to them.

Name of improvement	Base price	Strength gain	Price multiplier
Reinforced finger	15	+1	1.5
Auto-clicker	100	+5/sec	1.4
Coin factory	500	+20/sec	1.6
Crypto farm	2000	+100/sec	1.8

Don't forget to add a purchase availability check. The upgrade button should become inactive (grayed out) if the player does not have enough funds. This can be implemented in the Updatemethod by checking the condition if (coins < price) button.interactable = false;. However, for optimization, it is better to call this check only when the number of coins changes.

How to avoid number overflow?

If the numbers become astronomical (for example, 1.5e20), the standard long type no longer copes. In such cases, they use libraries for working with large numbers or implement a system of abbreviations (1K, 1M, 1B).

Saving the player's progress

Nobody likes losing their progress after closing the application. In Unity for mobile platforms, the de facto standard is to use PlayerPrefs for simple data or serialize to JSON/XML for complex structures. For a clicker with several types of currencies and improvements, JSON is better suited.

Create a model class SaveDatathat will contain all the saved fields: number of coins, level of improvements, time of last exit (to calculate offline income). Use the [Serializable]attribute to allow Unity to work with this class correctly. The save method will convert the object to a JSON string and write it to a file.

using System.IO;
using UnityEngine;

public static class SaveSystem
{
public static void Save(GameData data)
{
string json = JsonUtility.ToJson(data);
File.WriteAllText(Application.persistentDataPath +"/savefile.json", json);
}

public static GameData Load
{
string path = Application.persistentDataPath +"/savefile.json";
if (File.Exists(path))
{
string json = File.ReadAllText(path);
return JsonUtility.FromJson(json);
}
return new GameData;
}
}

Call the save method when the application is closed. To do this, use the event OnApplicationQuit or OnApplicationPause (when the game is minimized). On Android, this works almost always when the user presses the Home button or switches to another application.

When loading the game, check for the presence of a save file. If the file is not found (first run), initialize the data with default values. Also here you can implement the mechanics of accruing coins during the player’s absence, comparing the current time with the saved timestamp of the last exit.

Optimization and assembly for Android

Before the final assembly, it is necessary to carry out optimization. Mobile devices have limited battery and memory resources. In the project settings (Project Settings → Quality), disable unnecessary effects such as shadows or anti-aliasing if they are not critical for your 2D interface. Make sure that all textures are compressed into ASTC or ETC2format supported by Android graphics chips.

Check the code for heavy operations in the method Update. Calling methods, creating new objects (new) or searching for objects through FindObject inside the update loop can cause FPS drops. Cache references to components in the method Start or Awake.

⚠️ Attention: Before publishing on Google Play, be sure to disable logging (Debug.Log) in the release build, since outputting logs consumes CPU resources and can reveal the logic of the application to attackers.

When the project is ready, return to Build Settings. Click the button Build. Unity will prompt you to select a folder to save .apk the file. The assembly process can take from a few minutes to half an hour depending on the power of your PC. Once completed, you will receive an installation file that can be transferred to your smartphone via USB or uploaded to the Google Play developer console.

Frequently asked questions (FAQ)

Do I need to know the C# language to create a clicker in Unity?

Yes, a basic understanding of C# is required. Although Unity has visual tools, all game logic, including clicks, math, and saves, is written in scripts. However, for a simple clicker it is enough to know variables, functions and conditional statements.

Is it possible to create a clicker without using code (No-Code)?

There are plugins and visual scripting systems (for example, PlayMaker or Bolt) that allow you to create logic without writing code. But for a full-fledged game and optimization, knowledge of the basics of programming will still be an advantage.

How to monetize a clicker game on Android?

The most popular methods: displaying advertising banners (AdMob, Unity Ads), watching videos for a reward (receiving bonus coins) and in-game purchases (disabling advertising, currency packages).

Why is my APK file not installed on my phone?

Check whether installation from unknown sources is enabled on your phone. Also make sure that the version of Android on your phone is not lower than the one specified in Minimum API Level in Unity settings. Sometimes rebuilding the project and clearing the cache helps.

How to make the game run in the background?

Unity pauses code execution by default when minimized. To accrue resources in the background, you need to save the exit time and, at the next launch, calculate the time difference, accruing the required amount "retroactively", and not starting timers in the background.