Seems we need to define what is meant by "gamification" in this context. If we're just talking about tracking and making visible streaks, vocab words learned,

Seems we need to define what is meant by "gamification" in this context. If we're just talking about tracking and making visible streaks, vocab words learned, tenses mastered, etc. that seems fine; little different than in fitness training where one tracks workouts, miles run, pace improved, weights lifted, etc.. Adding in a few goals and milestones met can be helpful OTOH, if we're talking about skewing the content to maximize psychological manipulation at the cost of actual learning, that is toxic gamification, and certainly against the user's goals. Haven't used DuoLingo, so I'm not sure which one we have here?