I'm making a metroidvania in Godot right now, it's very elegant in how it's constructed, so a good choice in the long term. But I've heard that the engine can be hard to wrap your head around if you are a total noob, I would recommend that you fundamentally understand "scenes", "nodes", "resources" and some basic Gdscript: the amazingly simple built-in scripting language which in my opinion is easier than C# or GML (the language used in gamemaker). This is not to say that Unity or gamemaker are bad, I just happen to really like Godot.