[blindmute]

Yeah, I'd say it's about as polished as it can get, but it conceptually is just not going to be useful for any serious learning. It's been my experience over the years that the more enjoyable a language learning technique is to do, the worse it actually works. And duolingo is to their credit very enjoyable.

[smcl]

That's quite an astute observation - I guess getting out of your comfort zone is a necessary part of language learning. I've written on HN before about relatively simple things I have found useful (keeping a diary in $language, or watching films with $language audio) but looking back, if I'm honest the toughest situations were probably the most valuable for building confidence and testing my abilities.