I really love Portrait Prophecies and I think this game has a great concept, but I think specific parts have extremely poor design (either that, or I am doing something wrong without realising it.)
The most glaring example of this is the room with three doors and the tiny table in the left-hand corner with the big white thing on top. I tried and tried again, you can't hide under the tiny table; so, if you hear footsteps in this room (and I did, several times) you're totally screwed, because in this situation, doing anything but hiding results in game over. This is an unfair, no-escape situation which the player can do nothing about.
Additionally, it seems the difficulty increases exponentially immediately after finding her the first time. Steps and knocking seem to happen a lot more often, and often there's nearly zero time to react, which results in the game restarting over and over again before you can even understand what you did wrong. Thrill leaves room to frustration very soon. Not once did I manage to find her more than once before being caught.
Another thing (which comes across as a bug, though it might just be part of the atmosphere) is that at times you're suddenly teleported to a different room, no explanation given.
I would really like to play it through till the end, but it's simply too frustrating to spend time on.