The starter pack is for Unity. I assume we can use Unreal too? Is there an Unreal equivalent of the starter pack (or are they pretty transferable contents)?Thanks,
Matt
You sure can use Unreal or any other engine (although if it's an engine one has to pay for it would be difficult for others to take your project and learn from it).
Be aware, that games without a WebGL build are less popular because you can't just hit a "play" button on the game's web page. And it might limit your potential audience if there was only a Windows version of it.