If you've built a Unity game and want to distribute it as a professional .exe installer, you can use Inno Setup, a free tool that allows you to create custom installation packages. Follow this guide to generate an installer for your Unity game.

Step 1: Download and Install Inno Setup

First, download Inno Setup from the official website here and install it on your computer. https://jrsoftware.org/isdl.php

Step 2: Build Your Unity Game

After successfully building your game for Windows in Unity, the output folder should contain your game's executable file along with the necessary dependencies. The folder structure should look something like this:

Before proceeding, launch the .exe file to ensure the game works correctly.

Step 3: Open Inno Setup and Start a New Script

1. Open Inno Setup.
2. Click Create a new script file using the Script Wizard, then click OK.
3. Click Next to begin the setup process.

Step 4: Enter Game Information

In the Application Information screen, enter:

• Application name (your game's title)
• Version number
• Publisher name
• Website

Click Next to proceed.

Step 5: Configure Installation Directory

On the next screen, leave the default settings as they are and click Next.

Step 6: Add Application Files

1. In the Application main executable file field, select your game’s .exe launcher (e.g., MyGame.exe).
2. In Other Application Files, add the entire output folder of your game (MyGameBuild/).
3. Click Next.

Step 7: Configure Additional Settings

1. Click Next (leave everything at default).
2. In the Application Documentation step, add any relevant .txt files (e.g., README, license agreement). You can download a sample license file and customize it with your name.
3. Click Next.
4. Choose your preferred install mode or leave it as default.
5. Click Next.
6. Select the languages for your installer and click Next.

Step 8: Compiler Settings

1. Choose the Output directory where the .exe installer will be saved.
2. Set an Installer name (e.g., MyGameInstaller.exe).
3. Select a custom icon file (.ico) for the installer.
4. Click Next.
5. Skip the password step and click Next.
6. Click Next again and then Finish.

Step 9: Compile and Test the Installer

Once compiled, you will have an.exe installer file. Run it to install your game and verify everything is working correctly.

Congratulations! You've successfully created an installer for your Unity game using Inno Setup.