Beautiful environments, lively animations, great music. Well-written too, with a strong period feel; reminds me of Wilkie Collins.
The one-hit magpies were a little frustrating, and the surprise algebra was about as welcome as surprise algebra usually is. :) Also, while the backgrounds parallax beautifully in the horizontal, I do not think they should parallax this much (if at all) in the vertical.
The story is clever, but it would have been fun to have more agency in the discovery of the secret (rather than relegating that portion to the last cutscene).
Overall, a delightful little game with a great sense of setting.