Il-Deung's character design is perfect, with feir elongated head and beauteous features, and adds some levity to an otherwise melancholic story. It plays into the same type of comic relief as Goodnight Punpun, where the character's ridiculous and out-of-place appearance goes unacknowledged by all the people around fem. I thought the faces in general were drawn beautifully, but I didn't care for the way they recycled images (like of the theme park) or how they mixed photographs into the artwork.
The overarching theme of the story is "what it means to be a proper adult" and how the avoidance of becoming a "failure" can lead to a pressured and dissatisfied existence. Basically, it promotes the idea that people can maintain their responsibilities without having to give up on doing things which they want to do. Yes, bills need to be paid, but you can find a job that brings you some enjoyment rather than worrying about getting the highest returns for your educational investment. By interacting with a thirty-year-old magician who seems to have retained feir childish innocence, both Yoon Ah and Il-Deung come to realizations that the path they were heading down wasn't satisfying and that they needed to allow themselves to stop being so serious all the time.
The main dramatic tension stems from not knowing whether the magician is actually performing magic or if fe's just an insightful lunatic. The story hints at both at various points.