Yup that's what I'm talking about - the Spanish track added a concept of "purple" which is an advance on the broken ones - you can now take an additional set of lessons for one that shows up broken and it will never break for you again.
I think the Spanish track is likely one of the most advanced in terms of number of lessons and quality of teaching - though I expect the "learn English" tracks are equivalent or more advanced, I've just never looked at those.
Spanish track recently was updated... So my nearly complete to 7th milestone tree (had just 4 circles left at 3/5) turned into a tree with 9 milestones and all progress beyond milestone 5 was wiped.
I was pretty mad! It'll take a lot of time to complete it all, it hurt my achiever feelings pretty hard. Of course, more content is more learning, but with later milestones it gets very repetitive.
Oh nice. Mine (Hindi) definitely doesn't have that, it's also shorter than a lot of other older/more mature ones I think. (I've dabbled in the French one.) I'll certainly do it if it becomes available, but for now I've done all that is.
I think the Spanish track is likely one of the most advanced in terms of number of lessons and quality of teaching - though I expect the "learn English" tracks are equivalent or more advanced, I've just never looked at those.