Dana Abercrombie from The Koalition writes:
"Thanos (played to perfection by Josh Brolin), is the first Marvel movie villain to be given an origin story from his point-of-view that allows the audience to come to their own conclusion about him. Delivering one of the best performances in his career, Brolin carries the weight of Thanos in his entire body. He is bold, brutal, and focused. He is also full of heart and carries a deep painful regret that we’re able to witness in small isolated moments."