If you click on the door again whe will give you first one hint, then again an even more specific hint.
No we didn't have time to implement anything more unfortunately, although we will expand on the game after the Ludum Dare! Yes as of now.
I did not see the hint because I only clicked on the doorlock once.
That is one flaw in the game that adventure games usually don't have you needing clicking on things multiple times for something useful to happen with it. Except talking to characters now that I think about it, but even then its better to just exhaust dialog options than that.
But I'm looking forward to a more expanded version of the game.