This is a remix for people who already know the Turn A story, not an entry point. The film compresses character arcs so severely that newcomers watch a plot march forward without anyone to care about. For the devoted: it's watching Tomino reshape his own work in real time, minor dialogue shifts and animation tweaks that only matter if you've lived with the original series. The pacing gains something by cutting fat, though it cuts bone too. This exists to be rewatched alongside the TV version, not to replace it. It's a curator's choice, not a recommendation.
The first of the compilation films that retell Turn A Gundam, this movie covers the opening half of the series. Loran Cehack comes to Earth from the Moon as a spy, sent to scout the planet ahead of a planned lunar invasion. Living there, he grows to see Earth as his real home. When he uncovers a giant mech left over from a lost dark age, he takes up the fight to defend Earth in the war that follows. The film is a science fiction mecha drama built around action and conflict.