Game machine and program therefor

Provided are game machines for automatically changing the difficulty level of the game operation in the middle of the game based on an evaluation made on a player's game operation, and programs therefor. A game machine 1 determines, at least in terms of timing and type, whether the player's inputted button operation matches with the button operation designated by the game. If the button operation sees matching, the game machine 1 determines it as an operation success, and if the button operation sees no matching, determines it as an operation error. Based on the degree of operation success or operation error, the game machine 1 dynamically changes the difficulty level of the game operation in the middle of the game.