Looks like I hit the end.
But the screen is speaking italian instead of english.
Message translated in english says: "And in the end we went out to see the stars again".
Known bug?
it's not a bug. It's a (partial) citation from the last verse of the Inferno (Hell) part of The Divine Comedy, in its native language, and the game designer wanted to keep it that way on purpose.
Inferno, XXXIV
My Leader then, and I,
in order to regain the world of light,
entered upon that dark and hidden path;
and, without caring for repose, went up,
he going on ahead, and I behind,
till through a rounded opening I beheld
some of the lovely things the sky contains;
thence we came out, and saw again the stars.
Lo duca e io per quel cammino ascoso
intrammo a ritornar nel chiaro mondo;
e sanza cura aver d’alcun riposo,
salimmo sù, el primo e io secondo,
tanto ch’i’ vidi de le cose belle
che porta ’l ciel, per un pertugio tondo.
E quindi uscimmo a riveder le stelle.