Considering the experience, there is one thing that will make me choose one over the other and that is stability. The Unreal Engine 4.16.1 crashed about 5 times for me while I was working on the tutorials. In addition the Unreal Engine tutorial ends with LIGHTING NEEDS TO BE REBUILT message which I don’t really know how to fix yet and there’s no “punch” action on mobile.
Though I was able to deploy to a web browser using WebGL on Unity without much issues, the game play on the server is terrible to the point that there is no real point, you can see it in action with Veerodius.
As for Unity Engine, it generates (after a LONG LONG LONG build time compared to Unity). It works with their local server but trying to plop it onto the an HTTP server gets a `Module.asm is not a function` error as can be seen in Punchman.
However, regardless of the result, WebGL is terrible on both anyway so …