When comparing ImpactJS vs Godot, the Slant community recommends Godot for most people. In the question“What are the best 2D game engines?” Godot is ranked 6th while ImpactJS is ranked 55th. The most important reason people chose Godot is:
Every property can be animated.
Ranked in these QuestionsQuestion Ranking
Pro Extensive documentation available to support development
ImpactJS has an active user community that busily produces tremendous resources including videos, books, tutorials, walkthroughs and more. There are also comprehensive class documentation available.
Pro Excellent collision detection system
Impact provides 2 types of collision detection; static and dynamic collisions. Both of which are easily integrated into game development.
Many plugins are available, including one called Impact++ which adds features like pathfinding and dynamic lighting.
Pro Level editor
Built-in map editor with support for tiling, collision layers, and actors.
Works with Box2d physics library, comes with all worthwhile elements for actors built in.
Pro Truly cross-platform allowing developers to build for anything
Extending the reach of a game developed with ImpactJS is easy due to the cross-platform nature the framework. There are Considerations around performance, resolution and audio, however all can be appropriately addressed when in development. Works in the browser via Canvas, even on mobile. Easily translatable into a packaged app.
Pro Integrated animation editor
Every property can be animated.
Pro Unified game editor interface
All the game developing work is done inside one program: the engine editor. This feature is something only high end engines have. Even the scripting is done in the same program. No need for Eclipse or other front end editors.
Pro Can be deployed to multiple platforms
Deploy games to desktops (Windows/OS X/Linux), smartphones (iOS/Android/BlackBerry), and the web (HTML5 via Emscripten).
Pro Built-in physics
Add physics to 2D and 3D scenes, through rigid and static bodies, characters, raycasts, vehicles and more.
Pro Fully dedicated 2D engine, no hacks
Godot has a mature 2D engine with many features used by modern 2D games.
Pro Under constant development
This engine barely released one year ago has more than 1000 forks on github and about 100 developers. Not only that just a bit of browsing trough issues you will quickly find out the dev community loves new esp free technology and does not shy away from completely rewriting parts of the engine. The audio engine is being completely rewritten to use threads and so forth.
Pro Free and open source
Godot is licensed under MIT license. Anyone can grab the source from https://github.com/godotengine/godot, and compile the engine themselves.
Pro Instancing and node concept makes sense
The node and the instancing concept work very well and helps developers to structure content efficiently.
Pro Editor and runtime are fully cross-platform
You can run Godot on all 3 major operating systems (Windows/Mac/Linux) and build your game to all available platforms from each without any platform-specific work needed. All platforms including Linux are supported first class.
Pro Easy to learn scripting language
It can be used to add custom behaviors to any object by extending it with scripting, using the built-in editor with syntax highlighting and code completion.
A built-in debugger with breakpoints and stepping can be used and graphs for possible bottlenecks can be checked.
Pro Fun to use
An important aspect that can't be grasped without using the engine for a few days. The Interface is evolving nicely and making games is just fun.
The executable is portable and less than 40 MB in size.
Pro The list of supported languages is growing
Officially, Godot supported languages for now will be GDScript, C#(Mono), VisualScript and C++.
Pro User friendly UI for all your team
Non-programmers (musicians, artists, etc) can join the development easily.
Pro Drag & drop interface
Many parts of the editor allow you to drag & drop, which makes working with assets and scene trees a joy.
Pro Internationalization of the editor
You can change the language shown in menus. Godot translations: https://hosted.weblate.org/projects/godot-engine/godot/
Pro Friendly towards Version Control Systems
The engine is build not only to support version control but to really use it. Scene files for example which usually get compiled into some sort of unreadable data stay in a text format - that way you can actually see your changes in a version control system like Git.
Pro Really good community
The community is great and really cares about the engine. It is easy to get help and to be part of Godot's future.
The last update was in 2014.
Con Cost of $99
While most HTML5 frameworks are offered as free open source projects, ImpactJS has a one time cost and no free option.
Con Tileset management could be more efficient
The tileset creation and management is lacking common features found in more developed tileset managers. However, it features support for Tiled - the only downside being that it is an external program.
Con No built-in way to import atlases
Godot does not have an easy and automatic way to import atlases created by other tools. However, there are plugins that can be used to import atlases from other engines.
Con Very bad documentation
The documentation is poorly written, and has very few examples of real application and even fewer design guidelines about how to program a game in the engine.
Con 2DPhysics is weak compared to Box2d
Box2d has much more features.
Con NoAdmob or other AdNetwork support
Godot has no native support for implementing advertisements into your game.
Con Difficult to optimize
Godot has an OOP architecture. Everything is an object internally and data is spread among many classes, thus it's difficult to optimize (i.e. not cache friendly, difficuly to vectorize or paralellize, etc).
Read about "Data Oriented Design" for more info about the problems and solutions.
Con OSX app is a mess
Instead of one contained folder/file with an icon per normal it is a mess of files which is not at all suitable or distributable without further work after every compilation.
Con Hard for a Unity user
Coming from a Unity background, Godot engine is hard.