Gaming machine with progressive feature for paylines and playing method thereof

A slot machine executes a slot game by rearranging symbols that are arranged in multiple partitioned regions in a matrix including first to fifth columns and first to third rows. There are multiple paylines in these partitioned regions in the matrix. A player selects and specifies some of these paylines to be bet with game media. By betting the game media on each of the specified paylines, those paylines are activated in the slot game. When the rearranged symbols form a winning combination on any of the activated paylines, the player receives an award. Moreover, the slot machine performs a process to decide an award content for a progressive bonus along execution of the slot game in which the player bets the game media on all the paylines or a predetermined number or more of the paylines. The process to decide the award content for the progressive bonus may also be performed when the slot games in which the player bets the game media on all the paylines or the predetermined number or more of the paylines are executed continuously a predetermined number of times.