When comparing Crafty.js vs uScript + Unity3D, the Slant community recommends Crafty.js for most people. In the question“What are the best 2D game engines?” Crafty.js is ranked 34th while uScript + Unity3D is ranked 93rd.
Ranked in these QuestionsQuestion Ranking
Easy to learn, based on Entities and Components, the later being class-like objects that entities inherit.
Has open function binding systems, allowing easy creation of custom components.
Pro Automatically generates nodes for third-party script assets
uScript's nodes are a visual representation of actual code blocks, and it takes advantage of C#'s reflection capabilities to automatically create nodes for any scripts it finds in your project, regardless of the source. This makes it inherently compatible with pretty much everything.
Custom nodes can also be created by hand, for cases where the automatically created ones contain more elements than they actually need.
Pro Versatile flow diagram script model
Modeled after UDK's Kismet (the predecessor to UE4's Blueprint), uScript's scripts resemble flowcharts where each box represents a function or value, with connections between them representing program flow. This provides a better at-a-glance indication of game logic than a simple list of events, and makes complex behaviors easier to accomplish.
Pro Generates C# source code
Nodes are translated directly to C# files in your project. This is great for learning to code, and also for advanced users who can use uScript for fast prototyping and then further optimize the scripts if necessary.
Con No IDE
If you like having some huge GUI akin to Gamemaker, Unreal, Unity, etc, Crafty is not for you.
Con Not that easy to use
It's a lot more complicated compared to something like Playmaker. Same tasks take a lot more time.