The thing that makes it unique is that it uses characters, items and backgrounds from public domain 19th century literature, with character art by J. J. Grandville in the "Public and Private Life of Animals" books. The music is also from the public domain, as it will use transcriptions and adaptions of French romantic composers, most notably Camille Saint-Saëns. Even the font used in the game is over a century old.
The kickstarter has reached £6,000 over its £7,000 goal, and there is four days left in the campaign. So if it sounds interesting to you, head over to the Aviary Attorney kickstarter and pick a pledge tier.