Great concept! Your art style is good and cohesive, like it!
They pick-locking mechanic made trying to manage all the prisoners already in cells and prisoners running around fun! It made me wish you had more mechanics like that. I'm not sure what else they could do, but something to really make me have to manage them carefully and keep track of a bunch of different things. Maybe there could even be different types of prisoners, or obstacles to the dragging?
No real problems with the game, just think it has a lot of potential and could use more! Good job!