When comparing Gideros vs Phaser.io, the Slant community recommends Phaser.io for most people. In the question“What are the best 2D game engines?” Phaser.io is ranked 8th while Gideros is ranked 26th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Instant on device testing
Gideros provides on device players for iOS and Android that can be used to instantly try out your code directly from the Gideros IDE.
Pro Auto scaling and image resolutions
Gideros provides an easy way to target various screen sizes by providing automatic scaling options and choosing the best image resolution based on device screen automatically
Pro Local builds
You can build apps without an online dependency.
Pro Friendly & helpful community
Gideros has an active forum where you can find friendly and helpful advice.
Pro New features and improvements are released regularly
Gideros is being constantly updated and improved by the main developers.
Pro All in one studio, no complicated setup
Gideros Studio is incredibly easy to set up. Once installed it is very easy to create a new project or open one of the many example projects. Trying out an example on the desktop is two clicks away.
Pro Easy plugin architecture
Gideros Studio has a very powerful feature which enables developers to use a C/C++/Java/ObjC library next to Lua. This way it's possible to call the library functions under Lua, get the results and interpret them directly under Gideros Studio.
Pro Supports many platforms
Gideros supports iOS, Android, Windows, MacOS, WindowsRT, Windows Phone and HTML5 platforms.
Pro Amazing 2D performance
2D performance is amazing.
Pro Very easy to learn
Gideros uses the Lua programming language which is very easy to learn (and very powerful). There are some excellent video tutorials too, to help you get started. The Gideros forum community are also very friendly and helpful if you any any problems.
Pro Great community resources
Pro Built-in Arcade Particle system
Pro Very active development
This is one of the most developed frameworks right now.
Pro WebGL and Canvas rendering modes
You can choose WebGL or classic HTML canvas element for game rendering.

Pro Good tutorials, courses and books
There are plenty of great learning resources available for Phaser.io.
Pro Super-simple loading of assets
Pro Excellent tools for sprites
Pro Support for Arcade Physics, Ninja Physics and p2.js
Pro Easy to learn
Most tasks are done just using 2 or 3 lines of code.


Pro Very fast to develop with
If you're browsing Slant, you probably already have a JavaScript enabled browser, which is most of what you need to get started learning JavaScript. The requirement to run a server locally on your computer while developing might make things a little more difficult
Pro No install required
All you need to do is attach Phaser script to a HTML page even without installing any extensions.
Pro Easy to understand if you have used flash
Phaser provides a similar approach as to that of Flash games, where you can load assets and place them on a stage, and even improves upon the shortcomings of actionscript. It is very easy to shift from flash to HTML5 development because of this approach.
Pro You can run it in the cloud
You can use it in popular online editors like replit, codandbox, etc.
Pro Animating is easy
Pro Has separate versions maintained by developer and the community
The creator of phaser(photonstorm) has given the older(Phaser 2.0) source code to the community for their own maintenance, and has made Phaser 3.0 with a different style and approach, trying to make it easier for beginners to learn.
Cons
Con Few resources, but growing
Gideros has a small community, and therefore do not have as many "How to make a game" tutorials. However, there are a couple of excellent books available that can take you through the fundamentals.
Con The Gideros IDE is not as fully featured as other IDEs
The Gideros IDE is not as fully featured as other IDEs, but you can easily use the very powerful and compatible ZeroBrane Studio IDE.
Con Using Cordova to Export for Mobile
To export to mobile games you need to use cordova.
Con Official documentation is not so good

Con Poor performance
As long as your map is not larger than 600*400px, everything is fine.
Con Extremely many bugs
Con Developer ignores community needs
