Attack on Titan Part 1: Guren no Yumiya is the first compilation movie that retells the story of Attack on Titan by Hajime Isayama until the end of the Struggle for Trost arc.
The story continues in Part 2, which covers the story until the point where the first season of the anime ended. It was released on November 22, 2014 in theaters across Japan. It was rebroadcast on January 2, 2017 on MBS.
Overview: In the first compilation movie, episodes 1-13 of the anime are retold, retelling two story arcs: The Fall of Shiganshina arc and The Struggle for Trost arc, while leaving out a majority of the Humanity's Comeback arc.
Summary: The giant hand of a Titan is seen above Wall Maria, ominously looming over the Walls, as the onlookers below gape in awe. On that day, humanity received a grim reminder, on how they lived in fear of the Titans and were disgraced to live in the cages they called Walls. The Scout Regiment are traveling through a forest.
Source: Attack on Titan Part 1: Guren no Yumiya, available under CC BY-SA 3.0.