const int button = 6;
const int MAX_ROUNDS = 10;
int buttonState = HIGH; 
int lastButtonState = HIGH;
int counter = 0;

void setup() {
  // put your setup code here, to run once:

  Serial.begin(9600);

  // let button be an output 
  pinMode(button, INPUT_PULLUP); // why input pullup??
  //not pressed = high  

}

void loop() {
  // put your main code here, to run repeatedly:

  buttonState = digitalRead(button);

  if(buttonState == LOW && lastButtonState == HIGH)
  {
    counter++;
    Serial.print("# of presses: ");
    Serial.print(counter);
    Serial.println();
    delay(100); // for button bounce
  }

  lastButtonState = buttonState;

  //if(timesPressed >= MAX_ROUNDS)
  {
    // end game, winner!
  }

}