ScreeningNotes’s review published on Letterboxd:
Just to be completely up front I'd like to say that I'm a huge sucker for movies like this.
Insomnia is a detective mystery with a protagonist (Pacino) that doesn't have a firm grasp on reality after acquiring insomnia from working in a place where the sun doesn't set. There are a few fabulous scenes where we witness Pacino's grip slipping, and Pfister's wonderful lighting and composition give everything a slightly eerie and ominous air. Beyond that it was a fairly by-the-numbers thriller and definitely a disappointment after the masterpiece that is Memento, but for me the rather average story was elevated by the movie's uncertain grasp on reality.
It's also a movie about fantasy, one of my all-time favorite thematic topics. It's about Pacino's fantasy of himself, it's about Swank's fantasy of Pacino, and through the Robin Williams character it's about fantasy itself and the telling of stories.
It might not push any boundaries, but it's an undeniably fun time.