You can switch between Beginner and Intermediate level in the Profile menu, anytime.
The Intermediate level unlocks more topics immediately, so if you are an advanced learner, you can pick a more advanced topic. If you start on a Beginner level, you'll seamlessly slip into Intermediate. You can unlock the same topics over time, but you do it one by one, one after another.
Also, we keep expanding our available vocabulary and definitely plan to add even more. Stay tuned!