ImpactJS vs uScript + Unity3D

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.

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.

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.

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.

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.

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.

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.