Arduino LCD game not displaying

I am getting crazy on my Snake LCD game. I use an Arduino Mega and I’d like to use the LCD screen and the PmodKYPD for my Snake game. The problem is that it will not display anything, no matter which key I will press. Here is my code:

#include <LiquidCrystal.h>
#include "Keypad.h"

byte mySnake[8][8] =
{
....
};
 // keypad type definition
const byte ROWS = 4; //four rows
const byte COLS = 4; //three columns
char keys[ROWS][COLS] =
 {{'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'0','F','E','D'}};

byte rowPins[ROWS] = {
  37, 36, 35, 34}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {
  33,32, 31, 30}; // connect to the column pinouts of the keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

boolean levelz[5][2][16] = {
{{false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false},
{false,false,false,false,false,false,false,false,false,false,false,false,false,false,false,false}},

{{true,false,false,false,false,false,false,false,false,false,false,false,false,false,false,true},
{true,false,false,false,false,false,false,false,false,false,false,false,false,false,false,true}},

{{true,false,false,false,true,false,false,false,false,false,false,true,false,false,false,true},
{true,false,false,false,false,false,false,false,true,false,false,false,false,false,false,true}},

{{true,false,true,false,false,false,false,false,false,true,false,false,false,true,false,false},
{false,false,false,false,true,false,false,true,false,false,false,true,false,false,false,true}}
};

LiquidCrystal lcd(7, 6, 5, 4, 3, 2); 
unsigned long time, timeNow;
int gameSpeed;
boolean skip, gameOver, gameStarted;
int olddir;
int selectedLevel,levels;

int NUM_KEYS = 5;
int adc_key_in;
int key=-1;
char key_read;
int oldkey=-1;

boolean x[16][80];
byte myChar[8];
byte nullChar[8] = { 0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0 };
boolean special;

struct partdef
{
  int row,column,dir; //0 - up, 1 - down, 2 - right, 3 - left
  struct partdef *next;
};
typedef partdef part;

part *head, *tail;
int i,j,collected;
long pc,pr;

void drawMatrix()
{
  int cc=0;
  if (!gameOver)
  {
  x[pr][pc] = true;
  //for (i=0;i<8;i++) lcd.createChar(i, nullChar);
  for(int r=0;r<2;r++)
  {
    for(int c=0;c<16;c++)
    {
      special = false;
      for(int i=0;i<8;i++)
      {
        byte b=B00000;
        if (x[r*8+i][c*5+0]) {b+=B10000; special = true;}
        if (x[r*8+i][c*5+1]) {b+=B01000; special = true;}
        if (x[r*8+i][c*5+2]) {b+=B00100; special = true;}
        if (x[r*8+i][c*5+3]) {b+=B00010; special = true;}
        if (x[r*8+i][c*5+4]) {b+=B00001; special = true;}
        myChar[i] = b;
      }
      if (special)
      {
        lcd.createChar(cc, myChar);
        lcd.setCursor(c,r);
        lcd.write(byte(cc));
        cc++;
      }
      else
      {
        lcd.setCursor(c,r);
        if (levelz[selectedLevel][r][c]) lcd.write(255);
        else lcd.write(254);
      }
    }
  }
  }
}

void freeList()
{
  part *p,*q;
  p = tail;
  while (p!=NULL)
  {
    q = p;
    p = p->next;
    free(q);
  }
  head = tail = NULL;
}

void gameOverFunction()
{
  delay(1000);
  lcd.clear();
  freeList();
  lcd.setCursor(3,0);
  lcd.print("Game Over!");
  lcd.setCursor(4,1);
  lcd.print("Score: ");
  lcd.print(collected);
  delay(1000);
}

void growSnake()
{
  part *p;
  p = (part*)malloc(sizeof(part));
  p->row = tail->row;
  p->column = tail->column;
  p->dir = tail->dir;
  p->next = tail;
  tail = p;
}

void newPoint()
{

  part *p;
  p = tail;
  boolean newp = true;
  while (newp)
  {
    pr = random(16);
    pc = random(80);
    newp = false;
    if (levelz[selectedLevel][pr / 8][pc / 5]) newp=true;
    while (p->next != NULL && !newp)
    {
      if (p->row == pr && p->column == pc) newp = true;
      p = p->next;
    }
  }

  if (collected < 13 && gameStarted) growSnake();
}

void moveHead()
{
  switch(head->dir) // 1 step in direction
  {
    case 0: head->row--; break;
    case 1: head->row++; break;
    case 2: head->column++; break;
    case 3: head->column--; break;
    default : break;
  }
  if (head->column >= 80) head->column = 0;
  if (head->column < 0) head->column = 79;
  if (head->row >= 16) head->row = 0;
  if (head->row < 0) head->row = 15;

  if (levelz[selectedLevel][head->row / 8][head->column / 5]) gameOver = true; // wall collision check

  part *p;
  p = tail;
  while (p != head && !gameOver) // self collision
  {
    if (p->row == head->row && p->column == head->column) gameOver = true;
    p = p->next;
  }
  if (gameOver)
    gameOverFunction();
  else
  {
  x[head->row][head->column] = true;

  if (head->row == pr && head->column == pc) // point pickup check
  {
    collected++;
    if (gameSpeed < 25) gameSpeed+=3;
    newPoint();
  }
  }
}

void moveAll()
{
  part *p;
  p = tail;
  x[p->row][p->column] = false;
  while (p->next != NULL)
  {
    p->row = p->next->row;
    p->column = p->next->column;
    p->dir = p->next->dir;
    p = p->next;
  }
  moveHead();
}

void createSnake(int n) // n = size of snake
{
  for (i=0;i<16;i++)
    for (j=0;j<80;j++)
      x[i][j] = false;

  part *p, *q;
  tail = (part*)malloc(sizeof(part));
  tail->row = 7;
  tail->column = 39 + n/2;
  tail->dir = 3;
  q = tail;
  x[tail->row][tail->column] = true;
  for (i = 0; i < n-1; i++) // build snake from tail to head
  {
    p = (part*)malloc(sizeof(part));
    p->row = q->row;
    p->column = q->column - 1; //initial snake id placed horizoltally
    x[p->row][p->column] = true;
    p->dir = q->dir;
    q->next = p;
    q = p;
  }
  if (n>1)
  {
    p->next = NULL;
    head  = p;
  }
  else
  {
    tail->next = NULL;
    head = tail;
  }
}

void startF()
{
  gameOver = false;
  gameStarted = false;
  selectedLevel = 1;

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Select level: 1");
  for(i=0;i<8;i++)
  {
    lcd.createChar(i,mySnake[i]);
    lcd.setCursor(i+4,1);
    lcd.write(byte(i));
  }
  collected = 0;
  gameSpeed = 8;
  createSnake(3);
  time = 0;
}
void setup()
{
  levels = 5; //number of lvls
  lcd.begin(16, 2);
  startF();
}

void loop()
{
  if (!gameOver && !gameStarted)
  {
   key_read = keypad.getKey();  // get key press
   key = key_read - '0';
   if (key != oldkey)   // if keypress is detected
   {
      delay(50);  // wait for debounce time
      key_read = keypad.getKey();  // get key press
      key = key_read - '0';
     if (key != oldkey)    
     {  
       oldkey = key;
       if (key >=0)
       {
         olddir = head->dir;
         if (key==1 && selectedLevel<levels) selectedLevel++;
         if (key==2 && selectedLevel>1) selectedLevel--;
         if (key==4)
         {
           lcd.clear();
           selectedLevel--;
           newPoint();
           gameStarted = true;
         }
         else
         {
           lcd.setCursor(14,0);
           lcd.print(selectedLevel);
         }
       }
     }
   }
  }
  if (!gameOver && gameStarted)
  {
   skip = false; //skip the second moveAll() function call if the first was made

   key_read = keypad.getKey();  // get key press
   key = key_read - '0';
   if (key != oldkey)   // if keypress is detected
   {
     delay(50);  // wait for debounce time
      key_read = keypad.getKey();  // get key press
      key = key_read - '0';
     if (key != oldkey)    
     {  
       oldkey = key;
       if (key >=0)
       {
         olddir = head->dir;
         if (key==0 && head->dir!=3) head->dir = 2;
         if (key==1 && head->dir!=1) head->dir = 0;
         if (key==2 && head->dir!=0) head->dir = 1;
         if (key==3 && head->dir!=2) head->dir = 3;

         if (olddir != head->dir)
         {
           skip = true;
           delay(1000/gameSpeed);
           moveAll();
           drawMatrix();
         }
       }
     }
   }
   if (!skip)
   {
     timeNow = millis();
     if (timeNow - time > 1000 / gameSpeed)
     {
       moveAll();
       drawMatrix();
       time = millis();
     }
   }
  }
  if(gameOver)
  {

    key_read = keypad.getKey();  // get key press
    key = key_read - '0';
   if (key != oldkey)   // if keypress is detected
   {
     delay(50);  // wait for debounce time
      key_read = keypad.getKey();  // get key press
      key = key_read - '0';
     if (key != oldkey)    
     {  
       oldkey = key;
       if (key >=0)
       {
          startF();
       }
     }
   }

  }
}

Does anyone know something about this issue?