I thought *Transformers One* was quite good. It was fascinating to witness how Optimus Prime and Megatron evolved into who they are. Chris Hemsworth and Brian Tyree Henry were excellent choices for those characters, with Henry being especially memorable in his role. Keegan-Michael Key, Scarlett Johansson, and Jon Hamm also made a strong impression; I’d say it boasts the strongest acting among the films connected to Michael Bay from this franchise (even though it isn't officially part of the live-action movies, having Bay involved makes it feel like one). The animation is wonderful, with some truly beautiful imagery—the backgrounds especially. The musical score is also worth mentioning, and so is the humor; Key often leads the way in that area. I really don’t have any issues with this movie.

Source on TMDB