As a german, I feel the right side is much more alien to me than the left side (split at "Start here").

Is that circumstancial, or does it reflect some linguistic truth? Like, are the languages on the left one family, and the ones on the right another family, or however linguistic taxonomy would call that?

Maybe it's just that the left side includes all the germanic languages, so that feels more familiar. There are also languages on the left side where I have no clue what or where that might be. But much more so on the right side.