I am new in arduino trying to make race game. My problem is that my button (all buttons) is working sometimes and sometimes not. I am pretty sure that it's because of my code. Could you please help me with it? Here is my code:

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int pausebetween = 1;
int spaceBetween = 1;
int maxElemnets = 4;
int obstacleArray[4][2];
int obstacles[4] = {3,3,2,3};
bool gameStart = false;
byte player[8] =
{
 B00000,
 B00000,
 B10100,
 B11110,
 B11111,
 B11110,
 B10100,
 B00000
};
byte obstacle[8] =
{
 B11111,
 B11111,
 B11111,
 B11111,
 B11111,
 B11111,
 B11111,
 B11111
};
byte enemy[8] =
{
 B00000,
 B00000,
 B00101,
 B01111,
 B00101,
 B00000,
 B00000
};
byte empty[8] =
{
 B00000,
 B00000,
 B00000,
 B00000,
 B00000,
 B00000,
 B00000
};
byte fire[8] = 
{
 B00000,
 B00000,
 B00000,
 B11111,
 B00000,
 B00000,
 B00000 
};
int mat[2][24] = {
  {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
  {1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}
  };
int up = 0;
int down = 0;
int reset=0;
int atack=0;
void setup() {
 pinMode(9, INPUT);
 pinMode(8, INPUT);
 pinMode(7, INPUT);
 pinMode(6, INPUT);
 Serial.begin(9600);
 lcd.createChar(0, player);
 lcd.createChar(1, empty);
 lcd.createChar(2, enemy); 
 lcd.createChar(3, obstacle);
 lcd.createChar(4, fire); 
 lcd.begin(16, 2);
}
void loop() {
  up  = digitalRead(9);
  down  = digitalRead(8);
  atack  = digitalRead(7);
  reset  = digitalRead(6);
  if(atack){
    for(int i = 0; i<2;i++){
        for(int j = 0; j<23; j++){
            if(mat[j][i]==1){
              mat[j+1][i]=4;
              Serial.println(mat[j+1][i]);
            }
        }
      }   
  }
  if(reset){
    clearStage();
    gameStart = true;  
  }
  if(gameStart){
    generateObstacles();
    redrawGame();
    moveObstacles();
  }
  delay(1000);
   
 }
 

void generateObstacles(){
  int obscount = random(1,4);
  int types[4][2] = {{1,3},{2,1},{1,1},{2,1}} ;
  int type = random(0,4);
  for(int i = 0; i< obscount; i++){
    mat[0][16+i] = types[type][0];
    mat[1][16+i] = types[type][1];
  }
  int spacecount = random(2,5);
  pausebetween = obscount + spacecount;
}
void redrawGame(){
   for(int j = 15; j >= 0; j--){
    for(int i = 0; i < 2; i++){
      lcd.setCursor(j,i);
      lcd.write(mat[i][j]);
    }
  }
}
void clearStage(){
  for(int i = 0; i<2;i++){
        for(int j = 0; j<23; j++){
            if(i!=1 && j!=1){
               mat[i][j] =1;
          }
        }
      }
}
void moveObstacles(){
   for(int i = 0; i<2;i++){
        for(int j = 0; j<23; j++){
           if(mat[i][j]!=0){
            mat[i][j] = mat[i][j+1];
          }else{
            mat[i][j-1]=1;
          }
          if(mat[i][j]==4){
            mat[i][j-1]=0;
            mat[i][j-2]=1;  
           }
        }
      }
}