Kidou Senshi Z Gundam I: Hoshi wo Tsugu Mono

Both are mecha anime created and directed by Yoshiyuki Tomino. Also, these two movies summarize the events of the respective TV series. Since they are created by the same man, they have a similar style of storytelling. They focus on a war between two opposing factions, an overpowered mecha, and a lot of tragic moments. 

Both of these films summarize the events of the early episodes in their respective series, using new animation. Both have a young mecha pilot as a main character, who is thrown in the front lines of war and has to cope with the experience of killing and watching people die. 

Both movies summarize the events from their respective TV series. Both are space opera anime which focus on a large-scale mecha conflict, but also have many romantic elements which provide a contrast between war and love. Overall, both anime have a very similar vibe and atmosphere. 

Both are military science fiction anime that show the horrors of war in a realistic way. Many soldiers die in the line of duty, but also many civilians, in order to show the sorrow of the people when they lose their loved ones. So overall, both show how war can affect the lives of humans, as well as how they affect societies.