Well Yes and no, yes as in it's open source so you can get the engine and change stuff and no one can do nothing to you, you can change the name of the engine and the logo and add features and remove features and what not, it's all up to you so every code you write even the code for the engine is yours and no royalty attached whatsoever and no as in the engine is being built by 1000+ people on GitHub, there are people fixing bugs, adding features and just making the engine a whole lot better. So yeah that's that I really recommend Godot though it uses a python-like programming language and the UI is pretty friendly I do recommend you try it out.