For every other type of game, I would at least check out Godot 4 once it's had a stable 4.0 release. It's easy to learn, supports .NET, and it's actually not hard at all to modify and extend if you know C++. It even compiles from scratch relatively quickly.
Unity's biggest advantage is the Asset Store. If you want a bunch of third-party plugins to make your life easier, Godot has a long way to go.