When comparing Phaser.io vs GDevApp, 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 GDevApp is ranked 83rd.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Built-in Arcade Particle system
Pro Great community resources
Pro WebGL and Canvas rendering modes
You can choose WebGL or classic HTML canvas element for game rendering.
Pro Very active development
This is one of the most developed frameworks right now.

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.
Pro Quickly add behaviors to objects
Prebuilt behaviors can be added to objects. This is a very efficient way to add a physics engine or make a platformer game.
Lots of behaviors are included, from the most advanced (Physics, platformer, top-down movement) to really simple ones (like the behavior to destroy objects when outside the screen or the one to drag objects with mouse or touch).
Pro Powerful events system to create games without programming
No need for coding using this system which is clear and powerful: events are composed of conditions and actions.
Actions are launched when conditions are fulfilled. This is a very beginner-friendly way of making games and is still efficient for advanced usage, contrary to most other "block"/"drag'n'drop" systems.
Pro Intuitive interface
Pro Based on GDevelop
The entire webapp is based on GDevelop, an open source native game development software available for Windows & Linux, so it benefits from its advanced development.

Pro Can download an archive of the game source
Even though the tool depends on having a server up and running, you can download a copy of your game to run locally, or host somewhere else.
Pro Great UI
Sleek and user-friendly UI.
Pro Can export your game as HTML5 and for Android
Games can be packaged for Android without relying on any third party tool. You can also export your game and download it to host it on your server or let it be hosted on GDevApp.com.
Pro Shallow learning curve
Cons
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

Con Depends on a hosting service
If the website goes down or closes down, you'll no longer be able to develop your games using this system (but you can download a backup of your game from time to time and open it with GDevelop).
Con Cannot deploy native games
For now, games developed with GDevApp can only be deployed for the Web. Android deployment is in the works, but even then, they won't be native since they are built with web technologies.
