# Build a mobile game with an independent developer > To build a mobile game, you start with a small playable prototype, test whether it is fun and only then add content, art and store polish. Paying per milestone fits this order well. ErdiBuilds is an open marketplace where clients post app, SaaS, website and game projects, see which independent developers from the EU fit best based on what they have already built, and pay per milestone. Canonical: https://erdibuilds.app/build/mobile-game Last updated: 2026-11-06 (November 6, 2026) ## Games are built differently from apps A business app succeeds when it works. A game also has to feel good: how a tap responds, how fast a level loads, how the difficulty grows. Those things are hard to judge on paper, so the first goal is a prototype you can play. Common phone games are puzzle and casual games, card and board games, idle and clicker games, small platformers and trivia. Multiplayer, real time battles and big 3D worlds need much more work, so be clear about the scope. If your game should run in a browser tab, see [web games](https://erdibuilds.app/build/web-game). ## Typical technologies Most phone games are made in a game engine, which handles graphics, sound, input and publishing to both stores. [Find My Stack](https://findmystack.app/?project_type=mobile-game) can help you compare options. - Unity (A widely used game engine that builds games for phones, computers and consoles, mostly with C#.) has a large ecosystem and suits 2D and 3D games. See [Unity developers](https://erdibuilds.app/hire/unity). - Godot (A free open source game engine with a light editor and good support for 2D games.) is a good fit for smaller 2D games and is open source. See [Godot developers](https://erdibuilds.app/hire/godot). - Native code (Apps written with Swift for iPhone or Kotlin for Android instead of a game engine.) works for very simple games or when a game is mostly menus and cards. - A small back end for accounts, leaderboards and saving progress, for example with Supabase (An open source backend with a Postgres database, user login and file storage.) or Firebase (Google's backend service with a database, login and push messages.). - Ads and in-app purchases (Payments for digital content or subscriptions that usually go through the store billing of Apple or Google.) if the game earns money. Each needs its own setup and testing. ## An example plan in milestones This order keeps risk low because you see the game early. Each milestone is funded before work starts and runs 1, 2, 3, 4, 6 or 8 weeks. Milestones are from 50 to 2,000 each in your project currency. 1. For example, weeks 1 to 2, prototype: core mechanic with placeholder art. Decision point: is it fun? Adjust or stop here at a small cost. 2. For example, weeks 3 to 6, vertical slice: one polished level with real art, sound, menus and save. This is how the finished game should feel. 3. For example, weeks 7 to 10, content: remaining levels or modes, difficulty tuning, tutorial, settings. 4. For example, weeks 11 to 12, services: leaderboards, ads or purchases if planned, analytics, crash reports. 5. For example, weeks 13 to 14, release: device testing, store pages, age rating and privacy forms, launch. The weeks are for illustration. Developers set the length of each milestone in their proposal, and each real milestone runs 1, 2, 3, 4, 6 or 8 weeks. Tell the developer if art comes from you or an artist, because game art often takes longer than code. [How to split a project into milestones](https://erdibuilds.app/guides/how-to-split-a-project-into-milestones) shows other ways to cut a plan. ## What belongs in the project description - The core loop in two sentences: what the player does again and again. - Two or three games that feel similar, and what yours does differently. - 2D or 3D, portrait or landscape, single player or multiplayer. - Art and sound: who makes them, and what style you want. - How the game earns money, if at all. - Target phones and the oldest versions to support. - Number of levels or length of content for the first release. ## How to recognise a suitable developer Ask for playable builds or store links, not only screenshots. Check that the games run smoothly on modest phones, and ask how the developer tests on real devices. A person who asks about your core loop before the art style usually understands games. A match score (A number from 0 to 100 that shows how well a developer fits your project, with plain reasons such as shared technologies, similar past work, budget fit and availability.) helps sort proposals. A developer needs at least 40 to apply, and 80 or more gets a Top match badge. Check whether the engine you want is listed under Expert in. Developers are independent professionals, not our employees. ## Frequently asked questions ### Unity or Godot for a phone game? Both can ship to iPhone and Android. Unity has a bigger ecosystem and more ready made plugins. Godot is lighter and open source. The best choice is the engine your developer knows well. ### Does the developer also make the art? Not always. Some developers work with an artist, some use asset packs and some only code. State in the brief who provides what, so proposals are comparable. ### Why start with a prototype? It shows whether the idea is fun before you pay for art and content. A first milestone with only the core mechanic is a low cost way to learn. ### Who owns the game? Unless both sides agree otherwise in writing on the platform, the rights to the result of a milestone pass to the client once that milestone is paid in full. If the game uses third party assets or engine licenses, ask the developer to list them, so you know what you may publish. ### What if I do not like a delivery? You can request changes before you approve a milestone. If you both decide to stop, mutual cancellation is possible, and an admin can decide a dispute. ## Related - [Build a web game with an independent developer](https://erdibuilds.app/build/web-game): Plan a browser game people can play with one click: tools, a milestone plan, what to write in the brief and how to recognise a good developer. - [Hire a Unity developer for your game](https://erdibuilds.app/hire/unity): Unity builds 2D and 3D games for phones and the web. What a Unity developer does, what to ask, example milestones and how matching works. - [Hire a Godot developer for your game](https://erdibuilds.app/hire/godot): Godot is a free, open source game engine for 2D and lighter 3D games. See what to ask a Godot developer and how a game project is planned. - [Build a mobile app with a developer](https://erdibuilds.app/build/mobile-app): Plan an iPhone and Android app: typical technologies, an example milestone plan, what to put in the brief and how to spot a developer who fits. - [How to Split a Project Into Milestones](https://erdibuilds.app/guides/how-to-split-a-project-into-milestones): Split a software project into milestones that each deliver something you can see and approve. Rules, an example plan and a free planner tool. - [Hire a Developer to Build Something New](https://erdibuilds.app/help/build-new): Turn an idea into a working product. See how to prepare, how milestones structure the work and what to ask developers before you start.