When comparing Scratch vs libGDX, the Slant community recommends libGDX for most people. In the question“What are the best 2D game engines?” libGDX is ranked 1st while Scratch is ranked 49th. The most important reason people chose libGDX is:
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.
Specs
Question Ranking
Pros
Pro Visual
Code is represented as visual building blocks that makes it easy to understand how a program is put together.
Pro Easy to learn
Scratch is designed to teach computational thinking rather than focus on specific syntax. It was designed specifically to be easy to learn for anyone over the age of 8.
Pro Great starting point for kids
Scratch was developed specifically for kids ages 8 and up as an exciting way to introduce them to technology. It's designed to be easy to learn, but still provides good depth in computational thinking.
Pro No need to be able to type
Pro Can be used to create games
Pro Highly structured
The language is highly structured. Therefore, it gives you the essentials of how to think like a programmer and teaches you good programming practices from early on, so you could write clean, working and readable code in the future.
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 Lots of resources to learn from
Lots of references, tutorials and open source code to learn from.
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 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 Fantastic UI toolkit (scene2d)
scene2d is a 2D scene graph, scene2d.ui is a UI toolkit on top of that. It enables very complex mobile and desktop UIs.
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 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 Very easy to customize
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 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 Uses Box2D
A Java port of the Box2D physics engine is included in libGDX.
Pro Constantly improved
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 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 Similar to the Microsoft XNA framework
Old XNA users may like libGDX since it's API is actually very similar to XNA's.
Cons
Con Won't get you a job
Scratch is not a language used in the workplace. Instead it teaches computational thinking, helping to create a foundation to aid in learning other languages.
Con Does not teach you programming
Learning Scratch might help you if you have high difficulty with logical thinking. However, starting with a proper programming language, especially an easy one, will give you the benefits of starting with something like Scratch and everything else.
Con Not starter friendly
Even default applications fail to load in Android. It doesn't have any documentation on errors either.
Con Documentation could be better
Other than a brief installation / getting started overview, libGDX's documentation consists of an official wiki with several incomplete pages, and automated Javadocs. The community recognizes these shortcomings, and new users are encouraged to ask for help.
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.