There are some inherently dull and hard part of begging a new language. Duolingos gamification make learning things like the Korean characters or the basics of pronunciation a bit easier. But unless you’re making an additional effort to do language learning activities on your own over and above the app it’s probably not going be so useful. For instance try to recall all the content you’ve covered in a unit on your own and see if you can write it down. Or try and used some of the phrases to have a conversation with another learner etc..