Oh man, I loved this movie. Unlike Unfriended and Unfriended Dark Web (the latter of which I actually enjoyed quite a bit), Searching develops a deep emotional resonance from a beautiful opening sequence that tells its own heartbreaking story that serves as a preamble for the drama that's about to come. From there, the movie is a very cleverly plotted thriller that's also a deep emotional journey for John Cho's character.
As a thriller, Searching has a very tight script that's filled with enough turns so that when you finally reach a conclusion (or think you do), the movie goes another route. As the tension mounts and clues lead to either dead ends or new avenues of investigation, Searching's unique structure works with the audience to bring us along for the ride and invites us the follow the movie's breadcrumbs.
At its heart, however, Searching depicts a man who's desperation to find his daughter leads him to do some morally questionable things that fit well within the logic of the film. Things like setting up hidden cameras or confronting a potential suspect could have been played more for drama than anything else. But Cho channels an emotionally distraught father so well that his actions make perfect sense. As the movie unfolds, Cho's character goes to more arguable extremes, but from a character perspective, Cho's character is coming to terms with his faults as a parent in his relationship with his daughter. This characterization is so well done and so well acted by Cho that any action that a lesser film would have made gimmicky comes across completely heartfelt and sincere.
Finally, without going into specifics for fear of spoiling the movie, Searching's last 30 minutes or so were very gripping and brought the story to a very satisfying conclusion for me. I definitely recommend seeing this as fresh and in the dark as possible.