Honestly I don't think I've every finished a Twine game. But this one was so well done, and interesting! Loved it. The realization of who the killer really is over the course of gathering clues definitely put this above almost all escape the room fare. And I think it was really clever to have the situation on the face of it be very tropey 'escape the room game' at first but then actually serve an explanation for the strange locks, mechanisms and hidden clues.
Also I don't want to be too specific and spoil anything, but I appreciated having the 'date' be day first since it was supposed to be London.