Adverbs are usually a joke in IF. There's so much work to do just to make the game respond sensibly to straightforward actions that adding subtle qualifiers to those actions seems like an impossible task. Where they do appear, they tend to be used for conversation and other social contexts, where how something is done is as important as what is done. In the romance-parody Forever Always, for instance, you negotiate a fraught social situation (disrupting your lover's wedding without fatally irritating her) by using different verbs and adverbs for speech. ROAR ANGRILY gives different options than WHISPER LUSTILY, and gives those options different effects.
Danse Nocturne is a slighter piece even than the rather brief Forever Always; the verb is always DANCE and your only control lies in the selection of adverbs. The emphasis on tone and mood is reinforced by the writing, spare blank verse that focuses on the core of the story without giving much away beyond that. Avoiding the usual IF methods of detailed, object-oriented setting allows it to get away with a much more immediate, sparse, focused world than would normally be possible, and to deliver poetry without waffling. The core story, a revenger's tragedy that could be summed up in a line or two, emerges at just the right pace: not so slowly as to be irritating, but slowly enough to have dramatic impact. There's a well-maintained feeling of the epic or mythic. The Germanic naming style evokes a feeling of tragic saga.
Again, the core thing that the player does is not exploring the PC's range of action, but her range of attitudes, social styles, emotional responses. This ends up enabling action, but the game's core is: how should this character feel about this? It's about a character who is trying on different personas, seeing if any of them will help her -- a process at the heart of role-playing and of socialisation.
As a speed-IF, this is all quite brief and simple. While the game recognises a great many adverbs, the territory you negotiate with them is not complex; most adverbs give a single response and don't change the game-state. Play is mostly about thinking up new adverbs and trying them out. This is not to say that it should have been longer or more difficult: the strong poetic approach probably couldn't have been sustained over a bigger game. But it does leave me wistfully hoping for more substantial games that are navigated by manipulating tone, style, mood, focus, rather than medium-size dry goods.