I highly enjoyed this interactive short story. It really shows what you can do with strong writing, a fascinating idea, and Undum's elegant interface. Dias does a great job of hinting at a rich world filled with intrigues and dark machinations whose exploration lies beyond the scope of the story, but pervades it. The writing is dense and evocative, kind of Mievillian, but without Dr. Mieville's more unrestrained excesses of prose. I played through a couple of times and enjoyed seeing the different vignettes fit themselves into the larger story. I would love to read more stories, interactive or not, written in this setting. This is a great, enjoyable piece of fiction.
So much is accomplished here with about four verbs: smell, examine, bark, inventory. The PC is Sherlock's Holmes's faithful bloodhound Toby. And you're assisting Holmes to solve a murder by smelling various objects. On the face of it, this is a one-room game, but smelling something can evoke memories or scents relating to other locations in Toby's experience and you can thus traverse a wide array of very Victorian-British locales and social situations. The London that results is more Dickens-meets-Downton than Doyle, but it is rich and very detailed, providing commentary on nearly everything you can see, smell, and imagine. Groover has provided copious optional footnotes describing the various literary, IF, and pop-culture references in the game.
There's a sense in which the very limited verb-set in this game makes it seem somewhat choice-based. One could imagine re-creating it fairly completely in Twine. But Toby's Nose does a great job showing what the parser potentially does better. It demands an attention to detail (wholly appropriate in a Holmes mystery) that the clearly signaled hyperlinks in a Twine or other HIF story don't, and it permits actions that are off-script, which -- even though they're not necessary to complete the story -- add detail and background and humor that enriches the experience.
The story does tend to anthropomorphise Toby a bit, but it also doesn't forget that he's a dog. There's a wealth of (often funny) extra interactions and descriptive data built into the game to reinforce the canine perspective. Toby's smelling prowess also may seem a bit too impressive at times, but this can be forgiven as in service to a fantastic story. Toby's Nose is a truly impressive and accomplished piece of interactive fiction. Highly recommended.
Quick non-spoilery tip: it's possible to fairly easily brute force the solution to the mystery. (I did not solve it correctly on the first try or -- I'm ashamed to admit -- on the second try.) It may be helpful to know that the solution is obvious, not ambiguous, once you have all the requisite data. Don't cheat yourself by jumping the gun:)