Overall the film was uneven and poorly paced, but I liked the visuals of the titans. A few questions I had:
The first titan who kicked in the wall. Who was he and why was he bigger than the other titans?
When Eren became a titan, was the movie implying that's how new titans are born? Does the original story explain how Eren became a titan?
SPOILERS. MIGHT RUIN YOUR INTEREST
The Colossal Titan is Bertholdt in the manga/yet to be revealed in the anime. He's a quiet guy who turned out to be the Colossal Titan, obviously he's not in the film. As well as the Armored Titan and the Female Titan (maybe in the sequel). They are a trio of Titan Shifters who has unknown agenda.
No, that's not how Titans are born, right now they are still a mystery. Though some people are turned to Titans (long story). Eren's a shifter along with some. It's explained how he's turned into a Titan but I don't want to ruin it for you further.
Halfblood Camper #4
Valar Morghulis
His post is manga spoiler!
I only watched the anime... but I had already guessed what he wrote as first line so not big deal to me. I didn't read further though.
Please add the fact that it is from the manga to your warning :)