I tried German, but everything seemed to be lowercase even though the words.js on github seems to be fine regarding the special German capitalization.

Anyway, cool stuff. I once learned some latin by coding a simple program in C for terminal usage, basically just asking what is this word called, the wordlist file was specified as a command line argument. It was great and highly effective to memorize small chunks of words at a time. I still remember all those complex terms, so at least for me this type of learning works. This looks promising.