Game Of Mafia is an adventure game set in New York City in the mid 1920s. You play as Frank, an ordinary postman whose life changes dramatically after meeting with an old friend.

Link to the game on the Steam store

Instructions for activation keys to Steam:
1) Download and install the Steam client
2) Register an account or log in with your username in the existing one.
3) Go to the "My Games" and select "Activate via Steam ...", and enter the key received after payment.
4) Once activated, the game will appear in the game list (Library) and you can download it