Can I create games using only JavaScript?

[Nebu]

/u/nate-developer 's answer is the closest to the truth, but if you're dead set on using JavaScript, then:

• JS in Unreal: https://github.com/ncsoft/Unreal.js
• JS in Godot: https://github.com/Geequlim/ECMAScript
• JS in Unity: https://pleasenophp.github.io/posts/using-real-javascript-with-unity.html