[anmorgan]

I would actually say it is more of a game engine, especially when compared to three.js. Babylon.js supports physics plug-ins and collisions. They also have an action manager and other useful built in methods. Their tutorials are a really good place to start: https://doc.babylonjs.com/tutorials

Since babylon.js is more of a library, though, it doesn't have quite the tools to that something like Unity has, but they have great documentation and community support, and have a nice playground for testing small snippets. If you find an issue and post a question in the forum, I've gotten a fix in a matter of hours.

Note: User of babylon.js