Claudius started out trying to be a functional library that works like a fantasy console system like TIC-80or PICO-8: A way to do some retro-style demo graphics progeramming but in OCaml rather than in LUA. In its current form it doesn't do nearly as much as those fantasy consoles, instead just concentrating on enabling you to make graphical demos, and lacks things like audio, expressive input support, sprite editors and so forth. But if your goal is to enter something like Tiny Code Christmas or Genuary, then Claudius is designed for that use case.