A nice concept of a game! I really like the visual! :D
The thing I had an issue is the lack of information of what to do in the game. The game didn't really tell me what to do, besides I did understand that I must read the request of every customer that went into the bank. Maybe you could give it some kind of tutorial first in the beginning to teach the player of every action the player can do in the game.
Otherwise, I really like the game concept! and with the mechanic of defending yourself from robbers and homicidal customer with an AK47 is really unique twist! XD