yo i felt a bit stuck too, but i figured out that you can move some stones on the ground by pressing z (or enter) and move toward the black trail on the soil, if you try that on every possible stone block, you should be able to find a way out
though don't be afraid of getting lost in the ruins, eventually the path will appear by itself :)
have a problem: the difficulty to beat the ruin's 'boss', is it really high and you need to farm for a long time monsters to xp, or is there a feature that i don't understand in fights, am i too dumb to beat it...?