My non-biased review of the live action adaption of AoT
(I don't like the genre anime but I LOVE attack on titan, FMA brotherhood, and trigun...... Have not read any manga so any opinion is based off the show and OVA)
They altered the story of the show to fit a well arced story in 100 minutes so expect some alterations from the show. Story's not canon in half the story but it delivers a lot of soul punching moments
the story is actually darker and more realistic than the show which makes it (to me at least) a lot more interesting to watch in hopes they don't kill off the small amounts of characters the show hasn't killed off yet :P
also sasha is still cute AF
also: THAT *beep* ENDING THO
TL;DR if you like the show watch it. it changes details cinematicaly but deep down it stays canon to element of what the show is about. (it covers the first half of the first season)