Awesome! Take a look at Godot Engine. It's completely free (open-source) and no royalty cut if you succeed. It also deals with some nuances that Unity has (moderately advanced stuff). Offers 4 languages (visual script, gdscript, C# and C++). Visual script is like blueprints in unreal. gdscript is their own dynamic language (much like python + javascript kinda thing), C# - well, no need to explain this and C++ - they call it GDNative. It's their own system that allows you to create custom nodes (base entity in godot) in C++ without recompiling the entire engine .