1. When you see the enormous wall protecting the humans from the Titans.
2. When you spot the RED SCARF!
3. When you get your first glimpse of the Colossal Titan.
4. When the Titans feast on the humans.
5. When the Titans break down the walls and invade civilization.
6. When you the silhouettes of the creepy, empty-headed, but blood-thirsty Titans.
7. The first appearance of the canons being put to use.
8. When this human is yanked to its gruesome and certain death.
9. When we finally see the face of this UNBELIEVABLY HORRIFYING Titan.
JUST LOOK AT IT:
10. When we see this sweet Survey Corps. logo.
11. THE SALUTE!
12. When we see the "Omni Directional Mobility" gear in action.
13. When we see Mikasa being a total badass, slicing up the back of this Titan's necks.
Now, because this is a Japanese production, they used all Japanese actors to play the characters. Therefore, some of the original German/European characters from the anime had to be modified for the film.
14. Eren in real life looks like this.
15. Mikasa looks fierce AF.
16. Captain Levi is now Shikishima.
Levi's been replaced with a new character called Shikishima. To be fair, the dude comes off as a total boss in the trailer. Will he be more badass than Levi? Only time will tell.
17. Gone is Armin's beautiful blonde hair.
18. Jean looks like a total raging badass:
This casting makes perfect sense.
19. Sasha is ACTUALLY fighting instead of... well... eating.
Although it would've been cool to see her eat a steamed potato.
20. Hannes is now Souda.
21. Hange Zoë is now Hans.
The name might be different, but the spirit of the character is pretty much the same.