I’ve seen LibGdx for Kotlin JVM but I haven’t really seen anything else for Kotlin JVM or anything at all for Kotlin Native.
On Kotlin JVM you can use any java game engine (LibGdx, jMonkey, I’m sure there are some more, just google for them).
On the native side there aren’t any (as far as I’m aware). I guess you can try to use any C engine (creating the bindings yourself). I don’t know of anyone trying this, but I would guess it’s a lot of work. Also K/N’s performance isn’t that great, so maybe K/N isn’t the right choice for this. Of cause this will hopefully improve over time, K/N still isn’t stable so there will be lot’s of improvements/changes.
Korge is Here
and you can use Kotlin Native in Godot with a native wrapper .
Does it have similar speeds to stuff like Unity and/or Unreal Engine and what does it support? 2D or 3D or both?
I invite you to have a look at https://github.com/KogeLabs/Koge
Koge (Kotlin OpenGL Game Engine) is a 2D game framework developed in Kotlin that works in Windows, Linux and Mac OS X.
Also take a look at this: https://github.com/zeganstyl/thelema-engine
It is 3d engine, currently for desktop, but soon will also for webgl.