Bruno Ganz did not receive an Oscar nomination for portraying Damiel in Wings of Desire.
Bruno Ganz portrays the angel Damiel who observes the world and the lives of humans although he is not able to interact with the world. For about the first three fourths of the film Ganz's performance is very much a straight shot in terms of its consistency. Wings of Desire is very much, the director, Wim Wenders's film. Ganz is a part of it but a very important part portraying the angel who wants to stop just observing human behavior and become human himself. Even though this desire might sound like the arc for Damiel it is done very much as part of who Damiel is from the beginning of the film.
Ganz's performance is very much about his face and the manner in which he observes for most of the period in which he is an angel. Ganz as a wonderful welcoming quality in his performance and very much achieves what he needs to as the angel. There is nothing strange or even slightly creepy about him watching over the people because the goodness of Damiel is so effortlessly conveyed by Ganz. Ganz's performance accentuates the perfect pleasantness of the Damiel while still being otherworldly in just the right way. Ganz is inviting in his earnest face yet he mixes in the right separation as Damiel can only interact with the real world in the smallest ways.
Ganz really plays the longing to be human extremely well as part of who Damiel is. It is never something that drives Damiel from still being angelic in manner instead Ganz infuses within the curiosity of Damiel as he watches the world. Ganz carefully sets Damiel apart from the angels in the film through a strong but very subtle passion as he slowly tries to interact the world directly. It is steady mostly silent curiosity but Ganz establishes it well and in this way makes Damiel the most open seeming of all the angels as Damiel is an angel who wants to be a man. He still is at a distance but always leaves the potential for closeness.
Eventually Damiel falls and becomes a human although this is not done with a great deal of pomp or circumstance. Ganz's performance follows suit which works properly for the character of Damiel who definitely would not make sense to change the nature of his character. As the human Damiel Ganz adjusts his performance ever so slightly but it is a very effective approach as he doesn't compromise the nature of Damiel as a character. Ganz becomes earthly in his face and expression as the seeming perfection leaves to just a more normally emotional man. He still suggests a natural goodness but the goodness of a normal man rather then a heavenly creature.
Even though Damiel has made a big transition Ganz still goes along as Damiel as the curious man although now with even more life as he gets to interact with the physical for once. He brings a tremendous energy and joy in his performance and really brings to life the idea of a man first experiencing the smallest parts of life in a believable natural fashion. It is the last part of the film so there actually is not a great deal of time given to these scenes actually as Damiel experiences the world and tries to find a woman he fell in love with as an Angel. Ganz though gives a nice quiet work just letting all of the happiness of the journey of Damiel flow in fitting for fashion for his character whose journey should be a gentle but moving one.