I wonder why this discussion always falls to Unity and Godot; Unity source is not available, while Unreal Engine source is.
Unreal also has more features available than both engines out of the box, as far as I am aware. I don't want to sound like an advert, but the shading and Blueprint systems in UE4 are extremely intuitive and easy to work with, and the C++ is definitely managable. I've never used Godot, but the last time I compared Unity to UE4 it felt extremely clunky. Lastly, prototyping stuff in UE4 is fun, once you get used to it and develop your own workflow.
Unreal also has more features available than both engines out of the box, as far as I am aware. I don't want to sound like an advert, but the shading and Blueprint systems in UE4 are extremely intuitive and easy to work with, and the C++ is definitely managable. I've never used Godot, but the last time I compared Unity to UE4 it felt extremely clunky. Lastly, prototyping stuff in UE4 is fun, once you get used to it and develop your own workflow.