DIY Simple Arduino Whack-a-Mole Game

/*Arduino Whack-A-Mole Game 
by mircemk, June 2025
*/

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin Definitions
const int buttonPins[] = {8, 9, 10, 11, 12}; // Button pins
const int ledPins[] = {2, 3, 4, 5, 6};      // LED pins
const int buzzerPin = 13;                   // Buzzer pin (digital 13)
const int numMoles = 5;                     // Number of moles/buttons/LEDs

// Game variables
int currentMole = -1;         // Current mole (LED) to be lit
int score = 0;                // Player's score
unsigned long reactionTime = 1000;  // Initial reaction time (milliseconds)
unsigned long lastMoleTime = 0;     // Time when the last mole was lit
unsigned long gameStartTime = 0;    // Start time of the game
unsigned long gameDuration = 30000; // Total game duration (30 seconds)

// Reaction time adjustment
const unsigned long reactionTimeDecrement = 100; // Time to reduce reaction by (milliseconds)
const unsigned long minReactionTime = 300;       // Minimum reaction time (milliseconds)

void setup() {
  lcd.backlight();
  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(2, 0);
  lcd.print("Whack-a-Mole");
  lcd.setCursor(3, 1);
  lcd.print("by mircemk");
  delay(2000);
  lcd.clear();

  // Initialize button pins and LED pins
  for (int i = 0; i < numMoles; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);  // Set button pins as input with pull-up resistors
    pinMode(ledPins[i], OUTPUT);           // Set LED pins as output
    digitalWrite(ledPins[i], LOW);         // Turn off all LEDs initially
  }

  pinMode(buzzerPin, OUTPUT); // Set buzzer pin as output

  Serial.begin(9600); // For debugging and displaying the score
  randomSeed(analogRead(0)); // Initialize random seed from an unused analog pin
  Serial.println("Whack-a-Mole Game Started!");

  lcd.setCursor(2, 0);
  lcd.print("GAME STARTED!");
  delay(500);
  lcd.clear();

  gameStartTime = millis(); // Record game start time
}

void loop() {
  unsigned long currentMillis = millis();  // Get the current time

  // Update the progress bar
  unsigned long elapsedTime = currentMillis - gameStartTime;
  if (elapsedTime <= gameDuration) {
    int barLength = map(gameDuration - elapsedTime, 0, gameDuration, 0, 16);
    lcd.setCursor(0, 1);
    for (int i = 0; i < 16; i++) {
      lcd.print(i < barLength ? '-' : ' '); // Print '-' for remaining time, ' ' for elapsed
    }
  }

  // Light up a mole after a certain amount of time (based on reactionTime)
  if (currentMillis - lastMoleTime >= reactionTime) {
    if (currentMole != -1) {
      digitalWrite(ledPins[currentMole], LOW);  // Turn off the previous mole
    }
    currentMole = random(0, numMoles);  // Randomly pick a mole (LED)
    digitalWrite(ledPins[currentMole], HIGH); // Light up the chosen LED

    lastMoleTime = currentMillis;  // Update the time when the mole was lit
  }

  // Check if the player pressed the correct button for the lit mole
  for (int i = 0; i < numMoles; i++) {
    if (digitalRead(buttonPins[i]) == LOW) {  // Button pressed (LOW due to INPUT_PULLUP)
      if (i == currentMole) {
        score++;  // Correct mole hit
 lcd.setCursor(2, 0);
lcd.print(" Score:      "); // Clear the score field with extra spaces
lcd.setCursor(12, 0);
lcd.print(score); // Update the score

        tone(buzzerPin, 1000, 200);  // High-pitched sound (1000Hz) for 200ms

        if (reactionTime > minReactionTime) {
          reactionTime -= reactionTimeDecrement;
        }
      } else {
        score--;  // Wrong mole hit
 lcd.setCursor(2, 0);
lcd.print(" Score:      "); // Clear the score field with extra spaces
lcd.setCursor(12, 0);
lcd.print(score); // Update the score

        tone(buzzerPin, 400, 200);  // Low-pitched sound (400Hz) for 200ms
      }

      digitalWrite(ledPins[currentMole], LOW);  // Turn off the current mole
      currentMole = -1;  // Reset the mole to indicate no active mole
      delay(500);  // Short delay to debounce button press
    }
  }

  // End the game after the set duration
  if (elapsedTime >= gameDuration) {
lcd.setCursor(3, 0);
lcd.print("Game Over!   ");
lcd.setCursor(0, 1);
lcd.print("Final Score: ");
lcd.setCursor(13, 1);
lcd.print("   ");           // Clear any leftover characters
lcd.setCursor(13, 1);
lcd.print(score);           // Print the final score

// Flash all LEDs and play a sound three times
for (int i = 0; i < 3; i++) {
  for (int j = 0; j < numMoles; j++) {
    digitalWrite(ledPins[j], HIGH);
  }
  tone(buzzerPin, 1000, 300);  // Play sound
  delay(300);                  // Keep LEDs on
  for (int j = 0; j < numMoles; j++) {
    digitalWrite(ledPins[j], LOW);
  }
  delay(300);                  // Keep LEDs off
}

delay(2000);                   // Pause before resetting the game
lcd.clear();
score = 0;
currentMole = -1;
for (int i = 0; i < numMoles; i++) {
  digitalWrite(ledPins[i], LOW);
}
lcd.setCursor(0, 0);
lcd.print(" Start New Game");
delay(5000);
lcd.clear();
gameStartTime = millis();
reactionTime = 1000;
  }
}