Snake MOVEMENT (snake vs block) HELP!!!

Hi everyone, i have a problem with my snake movement like in Snake vs Blocks. I use 2 type of movement by accelerometer is perfect ma with finger not. Thanks to everyone than can help me. I would like a movement like in Snake vs Block. Also when i move snake with my sister the snake go trough cube or blocks sometimes, when the velocity is high.

 public class PallinaMovement : MonoBehaviour {
 
     public float pallinaSpeedX;
     public float pallinaSpeedY;
 
     //punto finale dello schermo cliccato
     public Vector3 endPos;
     public Vector3 startPos;
 
     public static PallinaMovement pallinaMovement;
 
     GameObject particles;
 
     void Awake(){
 
         if (pallinaMovement == null) {
 
             pallinaMovement = this;
         }
     }
 
     void Start () {
 
         SalvataggioNUOVO.control.Load ();
         pallinaSpeedX = 3.0f;
         pallinaSpeedY = 0.05f;
     }
     
     void FixedUpdate () {
 
         if (SalvataggioNUOVO.control.isAccelerometerEnable == false) {
 
             TouchAxisMove();
         } 
 
         if (SalvataggioNUOVO.control.isAccelerometerEnable == true) {
 
             AccelerometerMove ();
         }
     }
 
     void AccelerometerMove(){
         pallinaSpeedX = 5;
 
         float x = Input.acceleration.x;
             
         if (x < -0.1f) {
 
             MoveLeft ();
 
         } else if (x > 0.1f) {
 
             MoveRight ();
 
         } else {
 
             SetVelocityZero ();
         }
     }
 
     void TouchMove()
     {        pallinaSpeedX = 3;
 
         if (Input.touchCount >= 1)
         {
 
             Touch touch = Input.GetTouch(0);
 
             float middle = Screen.width / 2;
 
             if (touch.position.x < middle)
             {
                 MoveLeft();
             }
             else if (touch.position.x > middle)
             {
                 MoveRight();
             }
 
         }else{
             
             SetVelocityZero();
         }
 
     }
 
     void TouchAxisMove(){
         
         pallinaSpeedX = 3f;
 
         if (Input.touchCount >= 1  && Input.GetTouch(0).phase == TouchPhase.Began) {
             
             startPos = Camera.main.ScreenToWorldPoint (new Vector3 (Input.GetTouch (0).position.x, 0, 0));
             SetVelocityZero ();
         }
 
         if(Input.touchCount >= 1  && Input.GetTouch(0).phase == TouchPhase.Moved){
 
             endPos = Camera.main.ScreenToWorldPoint (new Vector3 (Input.GetTouch (0).position.x, 0, 0));
 
             float a = (endPos.x - startPos.x);
 
             gameObject.transform.position += new Vector3(a/50 ,pallinaSpeedY,0);
 
             ManageGame.manageGame.isMoving = true;
 
         } else {
 
             ManageGame.manageGame.isMoving = false;
             SetVelocityZero ();
         }
 
     }
 
     public void MoveLeft()
     {
         gameObject.transform.position += new Vector3(-0.03f,pallinaSpeedY,0);
     }
 
     public void MoveRight()
     {
         gameObject.transform.position += new Vector3(0.03f,pallinaSpeedY,0);
     }
 
     public void SetVelocityZero()
     {
         gameObject.transform.position += new Vector3(0,pallinaSpeedY,0);
     }
 
 
     void OnCollisionEnter2D(Collision2D coll){
 
         if (coll.gameObject.tag == "RomboNormale") {
 
             SalvataggioNUOVO.control.monete += 1;
             SalvataggioNUOVO.control.Save ();
 
             ManageGame.manageGame.moneteGameplay.text = SalvataggioNUOVO.control.monete.ToString ();
 
             ManageGame.manageGame.romboEffettoCoins.gameObject.SetActive (true);
             ManageGame.manageGame.romboSpecialeEffettoCoins.gameObject.SetActive (false);
 
             Invoke ("Disable", 1.5f);
 
             Destroy (coll.gameObject);
         }
 
         if (coll.gameObject.tag == "RomboSpeciale") {
 
             SalvataggioNUOVO.control.monete += 10;
             SalvataggioNUOVO.control.Save ();
 
             ManageGame.manageGame.romboSpecialeEffettoCoins.gameObject.SetActive (true);
             ManageGame.manageGame.romboEffettoCoins.gameObject.SetActive (false);
 
             Invoke ("Disable", 1.5f);
 
             Destroy (coll.gameObject);
         }
     }
 
     public void Disable(){
 
         ManageGame.manageGame.romboSpecialeEffettoCoins.gameObject.SetActive (false);
         ManageGame.manageGame.romboEffettoCoins.gameObject.SetActive (false);
     }
 }