Unity is still a solid engine, and since September 2024 its Runtime Fee is gone. But many indie developers now want an engine with no seat fees, or open source they control. These are the main alternatives in October 2026, with each engine’s licence and cost taken from its own site.
The short list
- Godot: the closest all-round replacement for Unity, 2D and 3D, free under MIT, with C# support.
- Unreal Engine: for high-end 3D. Free until a game earns $1M, then 5%.
- GameMaker: for 2D games. $99.99 once to sell.
- Defold: for lightweight 2D and mobile, with consoles. Free, source available.
- Stride and Flax: C# 3D engines. Stride is MIT; Flax charges 4% above $250K a quarter.
- Bevy and O3DE: open source, for programmers. Bevy is code-first Rust; O3DE is Linux and Windows.
- GDevelop: no-code 2D, with an MIT engine and paid publishing tiers.
Godot
- Licence and cost: free and open source under MIT. No fees or royalties.
- Languages: GDScript, C# (separate .NET build), C++ through GDExtension.
- Best for: 2D and stylized or mid-scope 3D, from solo developers to small teams.
- Consoles: for approved developers, through the official SDKs or porting partners such as W4 Games.
- Version: 4.7.2.
Most Unity concepts map one to one: a prefab becomes a scene, a MonoBehaviour becomes a script on a node, a ScriptableObject becomes a Resource. Our Unity-to-Godot dictionary lists 61 of them with code, and the Unity to Godot guide starts with a lookup chart.
Unreal Engine
- Licence and cost: free for game development until a title earns $1M in lifetime gross revenue, then a 5% royalty. A reduced 3.5% rate applies to games that launch on the Epic Games Store at the same time as other stores.
- Languages: C++ and Blueprints.
- Best for: photorealistic 3D, large worlds, larger teams.
- Version: 5.8, which Epic calls the last planned major Unreal Engine 5 release.
GameMaker
- Licence and cost: free for non-commercial use; a one-time $99.99 Professional licence to sell; an Enterprise subscription for consoles.
- Languages: GameMaker Language, as hand-written GML Code or block-based GML Visual.
- Best for: 2D games.
Our Godot vs GameMaker comparison goes into the differences.
Defold
- Licence and cost: free, source available under “The Defold License” (derived from Apache 2.0). No licensing cost, royalties or runtime fees. You must include its licence notice with your game.
- Language: Lua, with native extensions.
- Platforms: its site lists Xbox, PlayStation 5 and 4, Nintendo Switch, desktop, mobile and HTML5. Xbox support is free for approved Xbox developers from version 1.14.0.
- Version: 1.14.0 (October 2026).
Stride
- Licence and cost: editor and runtime open source under MIT.
- Language: C# 14 on .NET 10.
- Platforms: desktop and VR, per its site. Consoles are not mentioned.
- Version: 4.4 (October 2026).
Stride is the most Unity-like option if you want to keep writing C# in a 3D engine with an editor. It has a much smaller community than Godot or Unity.
Flax Engine
- Licence and cost: proprietary EULA with full source on GitHub. Free for non-commercial and educational use; commercial games pay 4% royalty on earnings above $250,000 per calendar quarter.
- Languages: C#, C++ and visual scripting.
- Platforms: Windows, Linux, macOS, Android, iOS, PS4, PS5, Switch, Xbox and web, per its feature list.
- Version: 1.13.
Bevy
- Licence and cost: open source under MIT or Apache 2.0.
- Language: Rust, with a data-driven (ECS) design.
- Note: its site does not mention a visual editor, so expect to build games in code.
- Version: 0.20 (October 2026).
O3DE
- Licence and cost: source code on GitHub “without any fees or commercial obligations”.
- Scripting: Script Canvas visual scripting and Lua.
- Platforms: the engine runs on Linux and Windows.
- Version: 26.05.
GDevelop
- Licence and cost: the engine and editor are open source under MIT. Publishing runs on Free, Silver, Gold and Pro plans. The free plan publishes to Android and desktop once per day, and companies with more than $50,000 in yearly revenue must use Pro.
- Best for: no-code 2D games and fast prototypes.
How to choose
- You want the closest replacement for Unity: Godot, especially if you make 2D or stylized 3D.
- You need top-end 3D visuals: Unreal.
- You want to keep writing C# in 3D: Godot’s .NET build, or Stride.
- You make 2D only: Godot, GameMaker or Defold.
- You need consoles on a small budget: check each engine’s console route before you start. Defold and Flax list consoles directly; Godot goes through approved developers and porting partners.
Engine terms change. Each fact above links to the engine’s own page in the sources, so check them before committing a project. For the three biggest engines side by side, see our Godot vs Unity vs Unreal comparison.
Frequently asked questions
- What is the best free alternative to Unity?
- For most indie developers it is Godot: free under the MIT licence with no fees or royalties, strong at 2D and capable at 3D, and it supports C#. Defold, Stride, Bevy and O3DE are also free; Unreal is free until a game earns $1M.
- Does Unity still have a runtime fee?
- No. Unity cancelled the Runtime Fee on September 12, 2024. As of October 2026, Unity Personal is free under $200K in revenue or funding, and Unity Pro costs $2,310 a year per seat.
- Which Unity alternative uses C#?
- Godot supports C# through its .NET build, Stride is written in C# and uses it for scripting, and Flax Engine supports C# alongside C++.
Verification notes
Sources and revision context
Published October 23, 2026.
Unity Unity pricing Unity Unity pricing updates Godot Engine Godot licence Godot Engine Godot on consoles Epic Games Unreal Engine licensing Epic Games Unreal Engine 5.8 GameMaker GameMaker pricing Defold Defold licence Stride Stride Flax Engine Flax Engine licensing Bevy Bevy O3DE O3DE overview GDevelop GDevelop pricing