Start with a game engine, not a blank screen

You do not write a mobile game from scratch in a text editor. You use a game engine — software that handles the graphics, sound, physics, and input so you can focus on what makes your game work. The two engines that dominate mobile development are Unity and Unreal Engine. Both are free to read and use until your game makes money.

Unity is the more common choice for mobile because it runs well on older phones and tablets, and it has the larger community of tutorials and asset stores. Unreal Engine is more powerful but heavier — it is better suited to games with complex 3D graphics. For your first game, Unity is the faster path.

read Unity from unity.com. The installer is large (several gigabytes) and takes time. You will also need to install a code editor — Visual Studio Community is free and comes bundled with Unity, or you can use Visual Studio Code separately. You do not need to understand how these work yet; the engine will guide you through the first steps.

Key Takeaways

  • Unity is the most common game engine for mobile and is free until your game generates revenue.
  • Your game starts as a project file in Unity, where you arrange objects on a screen and write code to make them move and respond to touch.
  • You write game logic in C#, a programming language that is easier to learn than many alternatives and has thousands of mobile game examples online.
  • Testing on a real phone during development catches problems that the computer simulator misses, and you can do this for free by connecting your phone to your computer.
  • Publishing to the App Store or Google Play requires a developer account (which costs money) and takes one to three days for review before your game appears.

Build your game in scenes and objects

When you open a new project in Unity, you see a blank scene — think of it as a stage. Everything in your game lives on that stage: the player character, enemies, buttons, walls, the background. Each thing is called a GameObject.

You create GameObjects by dragging them into the scene from the asset store, or by right-clicking in the scene and choosing what type to create. A straightforward mobile game might have a player sprite (a 2D image), some enemy sprites, a score display, and a button to restart. You position each one by dragging it where you want it on the screen.

Once objects are placed, you add components to them — small pieces of code that tell them how to behave. A player character needs a component that listens for touch input and moves the character left or right. An enemy needs a component that makes it patrol back and forth. A button needs a component that detects when you tap it and runs some code in response.

You write these components in C#, a programming language. If you have never coded before, this is the hardest part — but C# is designed to be readable, and mobile games use the same patterns over and over. A tutorial series will teach you the basics in a few days of practice.

Write code that responds to touch

Mobile games are controlled by touch, not a keyboard or mouse. Unity detects touch automatically, and you write code to respond to it. The most common pattern is: if the player touches the screen, move the character toward that spot.

Here is what that looks like in practice. You create a script (a file of C# code) and attach it to your player character. Inside that script, you write a function that runs every frame — about 60 times per second on most phones. That function checks whether the screen is being touched, and if so, moves the character.

Unity provides example code for this in its documentation, and thousands of tutorials show how to do it for specific game types. A puzzle game needs different touch code than a runner game, but the underlying idea is the same: listen for input, then change something on screen in response.

You do not need to memorize the code. You copy working examples, change the numbers to fit your game, and test to see if it works. This is how professional developers work too.

Test on your phone before you publish

The Unity editor on your computer has a play button that lets you test your game right there. But phones behave differently than computers — the screen is smaller, the processor is slower, and touch feels different than a mouse click. You need to test on a real phone.

Connect your phone to your computer with a USB cable. In Unity, go to File > Build Settings and choose iOS (for iPhone) or Android (for most other phones). Then click Build and Run. Unity will install your game on your phone and launch it. You can play it, find bugs, go back to the editor, fix the code, and test again — all without uploading anything to an app store.

This cycle is fast and free. Most developers test this way dozens of times before publishing. It catches problems that the computer simulator misses — a game might run smoothly in the editor but stutter on an older phone, or a button might be too small to tap accurately on a real screen.

Test on the oldest phone you can borrow. If your game runs well there, it will run well on newer phones too.

Prepare your game for the app store

Before you can publish, you need a developer account. For Android, go to Google Play Console and pay a one-time fee of $25. For iPhone, go to the Apple Developer Program and pay $99 per year. These accounts let you upload games and see how many people read them.

You also need to prepare your game's store page: a name, a description, screenshots, and an icon. The icon is a small image that appears on the phone's home screen — it should be clear and recognizable at small sizes. Screenshots should show the most interesting part of your game, not the menu screen.

In Unity, you create a final build of your game by going to File > Build Settings, choosing your platform, and clicking Build. This creates a file that the app store can read. For Android, the file is called an APK or AAB. For iPhone, it is an IPA file, but you usually upload it through Xcode (Apple's development software) rather than directly.

The process is different for each platform, and both have detailed guides on their websites. Follow them step by step — they change occasionally, and the official guides are always current.

Understand the review process and wait times

Once you upload your game, it does not appear in the store when ready. Google Play usually reviews Android games within a few hours to a day. Apple reviews iPhone games more slowly — typically one to three days, sometimes longer if they find a problem.

The review process checks that your game does not crash, does not steal data, and does not contain content that violates the store's rules. Most games pass on the first try. If yours is rejected, the store tells you why, and you can fix it and resubmit.

During review, your game is not visible to the public. Once it is approved, it appears in search results and category listings. You can update it later by uploading a new version — updates usually review faster than the initial submission.

Plan your game scope before you start coding

The biggest mistake new developers make is starting too big. A game with ten levels, five enemy types, and a shop system takes months to finish. A game with one level, two enemy types, and no shop takes weeks.

Write down what your game does: the player controls a character, taps the screen to jump, avoids falling rocks, and the score increases each second they survive. That is a complete game. You can add more levels and features later if you want.

Start with the smallest version that is still fun to play. Code it, test it on your phone, publish it. Then you know what the whole process feels like, and you can make a bigger game next time with confidence.

Frequently Asked Questions

Do I need to know how to code before I start?

No, but you will need to learn some C# as you build your first game. Tutorials teach you the specific patterns used in games — you do not need to understand everything about the language. Most people pick up enough in a few weeks of practice to make a straightforward game.

Can I make a game without using an engine?

Technically yes, but it is much harder. An engine handles thousands of details for you — drawing images, detecting collisions, playing sounds. Writing all of that yourself takes months. Use an engine.

What if my game crashes when I test it on my phone?

Check the error message in Unity's console window — it usually tells you which line of code caused the problem. Search for that error message online; someone else has probably hit it and posted a solution. This is normal and part of development.

How much does it cost to publish my game?

The game engine is free. A developer account costs $25 for Android or $99 per year for iPhone. Art, music, and other assets can be free (from asset stores) or cost money depending on what you choose. Your first game can be made for under $100 total.

How long does it take to make a mobile game?

A straightforward game with one level and basic mechanics takes two to four weeks if you work on it several hours a day. A game with multiple levels and more features takes two to three months. Professional games take much longer, but you do not need to match that for your first project.