To preface this review, I've already watched the first season of AoT in its entirety. I only watched this because I wanted to start watching seasons two and three, and I haven't watched this show since it came out; I needed a recap. It cuts out a lot from the anime (just over three hours of content), but in order to have just a story recap, it's alright. The scrap the military training, the politics (which might be for the worse later on), and some side character arcs. In the show, you get to grow close to the side characters and see them grow. The onlyone of those characters that still undergoes an arc is Jean, though I'll concede that his was the biggest one of all the side characters.
My biggest issue with this (from a film standpoint) is the pacing. It definitely feels rushed, and it makes total sense (considering it's the cliff notes of the first thirteen episodes of the anime), but it's not that bad. It just has a bunch of huge things happen in such a short amount of time instead of it being spread out evenly.
My final thought is, if you have a way to access it, watch the show. I give this 4/5 because I already know Attack on Titan, but I'd easily give 4.5/5 to the anime itself. It's bleak and haunting, but the characters shine hope in already hopeless situations, and that makes it worth watching.