Game Activities in Android (Unity/Godot)
Unity and Godot both support Android plugins. The Projects can be used as Activities in an Android App. As I mentioned I really not good at linking dependencies, the conclusion is that, unity has a better practice, but the App experience is still not good.
Unity
There is a video, Unity Android Integration: The Complete Guide. It is very detailed. However the problem in linking is about SDKs’ versions and environment variables. The project can be found here. Unity also provides sample project can be used as a template.
When running the activity, you still can see the Unity splash screen every time.
Godot
Godot recently supports Android plugins, there is not a document for that. However, I have not been able to run the example project. However, the godot player should be a runner for godot’s pck files. It feels more easier than Unity.
Conclusion
I think the WebGL way is more used than the two above.