>>106408592
this, a Lisp is an obvious choice
Common Lisp (first choice because its conditions system allows for correction of errors without annihilation of callstack, one can imagine programming a game, having a raised condition, correcting it, and resuming as you were).
Clojure for a functional Lisp on the JVM
Elixir has a good REPL too

anyway, Common Lisp would be the best option, its save-lisp-and-die feature allows for building up of software directly in the REPL and reloading later