I've tried to play and after a couple of tries it works, so thank you!
The problem is when you unzip the obb file, it creates two folders, one inside the other, and It seems the game can only read one for it to work. What you need to do is rename the first folder in something else, then move the sub-folder in sdcard/android/obb (it also works if you move it to the internal storage/android/obb) then delete the first folder (the one you renamed). This way the game shouldn't freeze on the loading screen. I thought I'd share in case somebody else is having the same problem. I'm bad at explaining and english is not my first language, but I hope it's at least understandable.
Thanks again!