Just finished the entire game, all routes.
Spoilers ahead!
I played through Emile's route first, where Denham isn't called out to in the hotel- and the entire route felt the most complete to me; with the romance hints between Emile and Lillian, the tension; so on, and I think the route was also the longest. With no true 'happy ending' to that route, I went back to the choice to choose calling Denham out, and that ending was far less satisfying.
I played all the routes afterwards in one sitting; and while I very much enjoyed the entire game, I do think my first run was the most satisfying; after a bit it felt somewhat like Anton always popped out of nowhere; this all-knowing man capable of always getting in the way of things. I suppose that's how spies are.
To a degree, I feel like the initial route just had the most work put in; we see the most of the side characters, we see more hints of Emile's personality, and his tension with Lillian makes the most sense there- her inherent attraction to him in Anton's routes make less sense to me personally, and feels less organic.
The heavier romance scenes being interrupted every time had me annoyed after a while XD but I guess I just wanted Lillian to get some.
Overall, I do think this game is phenomenal, the art is gorgeous, the writing is powerful, but I was expecting a more traditionally happy ending opportunity for the endings. When playing the first route, I thought with Emile (and not calling Denham out) the entire story would be the back and forth between Lillian and Emile; their warring personalities and inherent attraction, how he can't bite his tongue when needed, how she over analyses everything, and the writing really delivered that, but I feel like, to some mild extent, that the focus of the quality and length was reserved for that singular route; to be the 'true route' if anything.
When I finished all the routes, I wanted to see if a new secret route with a proper happy ending opened up, where Denham gets home, and Lillian has her beau. No such luck for me!
Still; a fabulous game, well worth the cost, thank you so much for all your effort, attention, and care. The music is wonderful, the art gorgeous, and focus put into the language was fantastic.