You should watch it. Is is the second cinematic release of 1997, after Evangelion: Death and Rebirth. The End of Evangelion is split is two parts denoted as episodes 24' and 25'. The first half of episode 25' is the Rebirth part of Death and Rebirth with some scenes reanimated and some new music; the rest is all-new. This cinematic adaptation is important because it provides an ending reported from a different, external point of view.