Pretty good! Translation by AI? First lessons quite well, but first quiz in German "Welche dieser Noten ist... ganze Tonoberhalb?" makes no sense.
Maybe I will find a middle ground and get translators just for the critical parts such as the challenges, or at least find a better way to translate parameterized strings like the one you are referring to.
EDIT: there is indeed an issue with some localized entries where the parameters are not placed properly, I will fix this for the next version