Good game for what it did. Graphics are very good, IMO transport the mood very well, together with the music. If you have ideas to expand this prologue, it would be worth the effort.
On the UI side, please show the actually used game keys on the unity input screen. I needed to press all the keys on my keyboard to find the 'use/open' key 'x'. In addition, let me change those keys on that input screen, because for example German/French keyboards don't have Z,X and C neatly aligned for one hand, the Z key is in the upper row.