Cool. I see you’ve made heavy use of the object system. If you’re interested in games built using the more idiomatic functional/ocaml approach (i.e. modules), you should check out a-nikolaev/wanderers.
I also wrote bramford/2d-exploration-game - a simple terminal/ncurses game while I was learning ocaml. I tried a couple of different approaches using the module system. I never felt that I got it quite right so while it is quite simple, it may not be the best example.