Tetris Block Phasing through grid

// using UnityEngine;

public class Tetromino : MonoBehaviour
{
    float fall = 0;
    public float fallSpeed = 1;

    // Use this for initialization
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        CheckUserInput();
    }

    void CheckUserInput()
    {
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            SafeMove(new Vector3(1, 0, 0));
        }
        else if (Input.GetKeyDown(KeyCode.LeftArrow))
        {
            SafeMove(new Vector3(-1, 0, 0));
        }
        else if (Input.GetKeyDown(KeyCode.UpArrow))
        {
            SafeRotate(90);
        }
        else if (Input.GetKeyDown(KeyCode.DownArrow) || Time.time - fall >= fallSpeed)
        {
            SafeMove(new Vector3(0, -1, 0));
            fall = Time.time;
        }
    }

    void SafeMove(Vector3 vec)
    {
        transform.position += vec;
        if (!CheckIsValidPosition())
        {
            transform.position -= vec;
        }
    }

    void SafeRotate(float degree)
    {
        transform.Rotate(0, 0, degree);
        if (!CheckIsValidPosition())
        {
            transform.Rotate(0, 0, -degree);
        }
    }

    bool CheckIsValidPosition()
    {
        foreach (Transform mino in transform)
        {
            Vector2 pos = FindObjectOfType<Game>().Round(mino.position);

            if (!FindObjectOfType<Game>().CheckInsideGrid(pos))
            {
                return false;
            }
        }

        return true;
    }
}

// using UnityEngine;

public class Tetromino : MonoBehaviour
{
    float fall = 0;
    public float fallSpeed = 1;

    // Use this for initialization
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        CheckUserInput();
    }

    void CheckUserInput()
    {
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            SafeMove(new Vector3(1, 0, 0));
        }
        else if (Input.GetKeyDown(KeyCode.LeftArrow))
        {
            SafeMove(new Vector3(-1, 0, 0));
        }
        else if (Input.GetKeyDown(KeyCode.UpArrow))
        {
            SafeRotate(90);
        }
        else if (Input.GetKeyDown(KeyCode.DownArrow) || Time.time - fall >= fallSpeed)
        {
            SafeMove(new Vector3(0, -1, 0));
            fall = Time.time;
        }
    }

    void SafeMove(Vector3 vec)
    {
        transform.position += vec;
        if (!CheckIsValidPosition())
        {
            transform.position -= vec;
        }
    }

    void SafeRotate(float degree)
    {
        transform.Rotate(0, 0, degree);
        if (!CheckIsValidPosition())
        {
            transform.Rotate(0, 0, -degree);
        }
    }

    bool CheckIsValidPosition()
    {
        foreach (Transform mino in transform)
        {
            Vector2 pos = FindObjectOfType<Game>().Round(mino.position);

            if (!FindObjectOfType<Game>().CheckInsideGrid(pos))
            {
                return false;
            }
        }

        return true;
    }
}