Honestly, I don't really know. I'm trying to do some research about this. In fact, This game is a knock off of Prison LIfe, and Redwood Prison. I'll respond when I am ready.
Your transit service, awaits.
First off, I wouldn't say "knockoff". Personally, it's more on the lines of "inspired". Secondly, I believe games like Jailbreak are the most popular because of their low complexity, but high depth of the gameplay.
By complexity, I mean "What do you need to know before you can get to properly play the game?"
All you need to know is the simple controls (sprinting, crouching, vehicle movement), how to obtain certain stuff like guns and keycards and how to use them, and the functions of places in the maps. Learning about how to play the game is slowly developed as you escape the prison and explore the map.
Depth is where the "fun" aspect of this game comes into play.
Both the police and the criminals have several options on what to do. The police have to think about where the criminals are and have clever ways of arresting them, while the criminals have to get the most money possible without having the police arresting them.
These choices are made by the player, and the user interaction between themselves, the game, and other players is how this game stays active.
It's why games like Jailbreak manage to stay on the top, while these "simulator games" such as Cash Grab Simulator fall to the bottom within a few days.
i mean jailbreak is full different stuff than prison life. Prison life is like you always get shot at, even when your a criminal, you get shot as a prisoner. one time i got shot by a criminal when i was a prisoner.
Well Jailbreak has a decent concept on paper. It's a good prison game but it gets boring briefly after playing because the only goal you really have is to get enough money to buy a ferrari or something. There could be so much more to this game.