I'm working on a game engine right now (written in object oriented language, of course) and I keep itching to design a compiled functional language for games, because state spread in thousand of objects, eldritch class hierarchies, are complete hell.

Once you taste Elixir/Erlang, there is no going back to the madness.

The confusing state riddling here happens in the background as your whole app basically is a state. The thing that really throws me off with Elixir is having to handle (possibly) hundreds of thousands of processes. Doing this correctly seemed impossible to learn for me.