OSU! Catch the Beat Game on Homemade 8x8 Matrix

int row[] = {12, 11, 10, 9, 8, 7, 6, 5};
int col[] = {4, 3, 2, A0, A1, A2, A3, A4};
int joystick = A6; //it is a simple potentiometer
int lastUpdate;
int puntos = 0;
int vidas = 10; //number of lives
int speakerPin = 13;
int SPEED = 0;
bool updatedAsteroid = false, updatedPlayer = true;

typedef struct coordenada {
  int x; //column coordinate
  int y; //row coordinate
}COORD;

COORD asteroid, jugador;

void setup() {
  // put your setup code here, to run once:
  
  for (int i = 0; i < 8; i++)
  {
    pinMode(row[i], OUTPUT);
    pinMode(col[i], OUTPUT);
    digitalWrite(col[i], HIGH);
    digitalWrite(row[i], LOW);
  }
  pinMode(speakerPin, OUTPUT);
  initGame();
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i = 0; i < 2; i++)
  {
    clearScreen(); //clean the led matrix
    if(lastUpdate == 1) {
      movePlayer();
    }
    if(lastUpdate == 0) {
      asteroidFall();
      //Serial.print ("The asteroid changes position !! \ n");
    }
    lastUpdate = Update(); //update the array of LEDs according to movePlayer () and asteroidFall ()
    delay(SPEED);
  }
  puntuacion(); //calculates the score and increases one life per point, when the player runs out of lives it goes to gameover () to restart the game
  if (asteroid.y == 8 || asteroid.y > 8) {
    initasteroid(); //initialize a new asteroid when the previous one has already dropped
  }
}

void initGame() {
  vidas = 10;
  puntos = 0; //points
  SPEED = 25;
  initplayer();
  initasteroid();
  return;
}

void initplayer() {
  jugador.x = 3;
  jugador.y = 7;
  digitalWrite(col[jugador.y], HIGH);
  digitalWrite(row[jugador.x], LOW);
  return;
}

void initasteroid() {
  asteroid.x = random(0, 7);
  asteroid.y = -1; //so that asteroid Fall () starts at 0 as soon as it is executed
  digitalWrite(col[asteroid.x], LOW);
  digitalWrite(row[asteroid.y], HIGH);
  return;
}

void movePlayer() {
  int value = analogRead(joystick);
  value = map(value, 0, 1023, 0, 7);
  value = constrain(value, 0, 7);
  //Serial.print("joystickX: ");
  //Serial.print(jugador.x);
  //Serial.print("\n");
  if(value >= 0 && value <= 7) {
    jugador.x = value;
  }
  return;
}

void asteroidFall() {
  asteroid.y++;
  //Serial.print("AsteroidY: ");
  //Serial.print(asteroid.y);
  //Serial.print("\n");
  return;
}

void clearScreen() {
  for (int led = 0; led < 8; led++)
  {
    digitalWrite(col[led], HIGH);
    digitalWrite(row[led], LOW);
  }
  return;
}

int Update() {
  if(updatedAsteroid == true && updatedPlayer == false) {
    digitalWrite(col[jugador.x], LOW);
    digitalWrite(row[jugador.y], HIGH);
    updatedAsteroid = false;
    updatedPlayer = true;
    //Serial.print("Player Updated !! \ n");
    return 0; //returns that the player has been updated
  } else {
    digitalWrite(col[asteroid.x], LOW);
    digitalWrite(row[asteroid.y], HIGH);
    updatedAsteroid = true;
    updatedPlayer = false;
    //Serial.print ("Asteroid Updated !! \ n");
    return 1; //returns that the asteroid has been updated
  }
}

void puntuacion() {
  if(asteroid.y == jugador.y && asteroid.x == jugador.x) {
      digitalWrite(speakerPin, HIGH);
      puntos++;
      delay(100);
      digitalWrite(speakerPin, LOW);
      vidas += 2;
      if(SPEED > 9 && puntos >= 4) {
        SPEED--; //SPEED up the game (new level)
        puntos = 0; //We restart the punctuation when we go to the next level
      }
      Serial.print("Points: ");
      Serial.print(puntos);
      Serial.print("\n");
  } 
  if(asteroid.y == jugador.y && asteroid.x != jugador.x) {
      vidas--;
      Serial.print("Vidas: ");
      Serial.print(vidas);
      Serial.print("\n");
      if(vidas == 0) {
        gameover();
      }
  }
  return;
}

void gameover() {
  //animation when you lose the game
  for(int y = 0; y < 5; y++)
  {
    //Serial.print("Animacion: ");
    //Serial.print(y);
    //Serial.print("\n");
    //loop that turns off all LEDs in the matrix
    digitalWrite(speakerPin, HIGH);
    for(int i = 0; i < 8; i++)
    {
      digitalWrite(col[i], HIGH);
      digitalWrite(row[i], LOW);
    }
    delay(500);
    //loop that turns on all the LEDs of the matrix
    for(int i = 0; i < 8; i++)
    {
      digitalWrite(col[i], LOW);
      digitalWrite(row[i], HIGH);
    }
    digitalWrite(speakerPin, LOW);
    delay(500);
  }
  delay(3000);
  initGame(); //initialize a new game
  return;
}