In Rio, Mrs. A and I also went to the movies. We saw a fairly bad movie starring Julia Roberts and Clive Owen (I think it was called Duplicity?), but the experience was fun.
Like Germany, there were assigned seats. However, you could pick them in advance from a computer screen. Sadly for me, when they turned the screen around to face me, I just assumed it was a touch screen and repeatedly tried to manually select the seats we wanted to the great alarm of the clerk and the great amusement of the people in line behind me. The bus we took from Rio to Angra dos Reis also had assigned seats (this may be more common, I have to confess that I don't take the bus much!) and people seem to take their seat assignments fairly seriously.
There was also a separate line for senior citizens!
Snacks were different from the US. There was popcorn and soda, but no candy bars. People were eating dessert items and even sandwiches at tables by the concession stand before the film started. There was very little eating inside the screening room. From what we saw overall, there are few obese people in Brazil (even compared to Mexico, let alone the US).
Prices were amazingly high, more than $10 per ticket, but at least there was no intermission.
The film was subtitled, but not very well. Mrs. A and I can both read Portuguese pretty well and were cracking up a few times at the differences between the spoken English and the written Portuguese.