When comparing libGDX vs ct.js, the Slant community recommends libGDX for most people. In the question“What are the best 2D game engines?” libGDX is ranked 12th while ct.js is ranked 41st. The most important reason people chose libGDX is:
Lots of references, tutorials and open source code to learn from.
Ranked in these QuestionsQuestion Ranking
Pro Lots of resources to learn from
Lots of references, tutorials and open source code to learn from.
Pro Great performance across devices
While it may not always have the best performance for a particular device or system, it's one of the few engines which consistently performs very well across different platforms.
Pro Allows you to migrate from 2D to 3D within same framework
LibGDX supports both 2D and 3D game development. Allowing developers to migrate from 2D to 3D with ease without having to switch the engine they are using or having to learn a new API.
Pro Doesn't force a specific design
Unlike some engines, which only allow you to make your game in a few specific ways, libGDX allows you to design any type of game you wish as it is extremely customisable.
Pro Active and helpful community
The libGDX community, in the official libGDX forum is extremely helpful and approachable for any kind of question regardless of the its quality or difficulty.
The forums themselves are a very helpful resource for any issue or guide simply by searching past posts in there.
In addition to the forums, there's also the official #libgdx IRC channel on Freenode.
Pro Uses Box2D
A Java port of the Box2D physics engine is included in libGDX.
Pro Interfacing with platform specific code
Sometimes it is necessary to access platform specific APIs, e.g., adding advertisement services or leaderboard functionality provided by frameworks.
Pro Can use any JVM language
Since it's built with Java and runs on the JVM, any language that compiles to Java bytecode can be used to develop games with libGDX.
Pro Free, open source & permissive license
libGDX uses the Apache License 2.0.
Not only is libGDX free and open source but also it's license gives you a lot of power over the engine. As long as you provide a copy of the license, give credit, do not hold devs liable and do not use libGDX logo in any engine forks you can do pretty much anything you want.
Pro Very easy to customize
Pro Support for 3rd party tools
libGDX has built in support for many 3rd party tools, including (but not limited to) Bullet Physics, Box2DLights and the well-praised Tiled Map Editor.
Pro Constantly improved
LibGDX itself is pretty mature, and get updates not quite frequently, but various libraries for it are actively updated.
Pro Across platform support
You can write once and run anywhere (Android, IOS, Desktop, Browser) also lately came with lib to deal with VR.
Pro Lots of tutorials to get you going
Even though the official documentation might be lacking, there are many tutorials on YouTube for libGDX.
Pro Excellent font rendering support
Very good tools for rendering fonts.
Pro Similar to the Microsoft XNA framework
Old XNA users may like libGDX since it's API is actually very similar to XNA's.
Pro Focusing on object pool patterns, to control memory without pointers
Unlike Unity or other engine, it allows to optimize a language that uses garbage collector when using patterns of objects you can control the use of memory without needing a language like C / C ++, getting the same speed in a more productive language.
Pro Kotlin support
It is written in Java so you can easily make games using Kotlin and Ktx project will help you get all advantages of this language.
ct.js is bundled with examples, docs, and easy to follow tutorials. Documentation and tutorials are available in a side panel on every screen.
Pro Skeletal animations with DragonBones support
You can import skeletal sprites and animations from DragonBones, which is also free. Skeletal animations are added to objects through code; developers can listen to marked events in animation, and ct.js automatically associates sounds in a DragonBones project with the game's assets.
Pro Good code editor
The built-in code editor comes with error checking, type checks, code completions accompanied with docs, multiple cursors support, and other modern features.
Pro Open source (MIT)
This means that no one will ever put any features behind a paywall and that you can reliably use ct.js in any projects without worrying about licensing. And you can hack on ct.js!
The repo is at https://github.com/ct-js/ct-js
Pro Tileset support
ct.js supports tiles in rooms, including collision checks and some extra editor tools, like bulk migration to a new tile layer or shifting by an exact value.
Pro WebGL and WebGL2 support
Starting with v1.0.0-next-1, you can now write WebGL games. WebGL support is based on Pixi.js.
Pro Modular approach
ct.js has a "Core" library that provides basic drawing functions, room and asset management, and mouse interactions. Any other functions are added to projects as "catmods", or simply modules. These modules can be enabled or disabled in one click, and can inject their code in different game loop stages, e.g. after drawing all the objects, leaving a room, or when a new object is created.
Pro Applicable to most genres
ct.js aims to be a general game engine and provides tools in making games of any genre.
Pro Dialogue and visual novel system with support for Yarn
A module ct.yarn allows developers to import a YarnSpinner project to create branching, data-driven dialogues and visual novels. An example is also bundled with ct.js.
The dialogue tree is made in a separate app, though.
Con Not starter friendly
Even default applications fail to load in Android. It doesn't have any documentation on errors either.
Con The project slowed down in development
The number of active developers has decreased, many open issues and pull requests.
Con Build system is clunky
LibGDX uses Gradle, which is very demanding of memory and makes IDEs freeze on anything if your computer is not powerful enough.
Con Does not create compiled code
LibGDX runs entirely on Java and does not create executable binaries.
Con A bit difficult to use
This engine is not well put together. Is made from various free modules each with their own peculiarities. At times it feels you need to learn a couple of libraries rather than just one. Is not an engine for beginners as it requires coding. Lots of coding. You need to be intermediate to advanced in Java to develop in LibGDX.
Con Tile editing is a chore
No live brushes with automatic corner drawing, no fills or rectangular/linear placement. All tiles should be placed by hand, with a "Shift" key to place multiple tiles at once. This will make you ragequit if you want to make sophisticated RPG scenes :D
Con No built-in particle system
Con Slower than native games