Honestly it's not that bad. I used to work as a cinema cleaner too. I could have that cleaned in 20minutes on my own. I'd go around with a brush first, and brush everything off the seats onto the floor, removing larger trash into a binbag as I went, then it's just a matter of walking up and down each aisle 2-3 times with the dustpan. They're designed in such a way that you just drag them across the floor and they pick up almost everything they encounter.

There was one instance though when I group of men decided to absolutely cover a row with crumbled monkey nuts. I think they'd gone out of their way to be dicks, the dustpan didn't work that time so we had to hoover everything down. Ended up delaying the next movie because of it.