How to make the player move on "slide" in Unity?

Question

I’m new to Unity and I’m doing the tutorial Roguelike 2D. By default the player will move, theoretically, using one of those coordinates per shift y+1, x+1, y-1, x-1, or just one block at a time. And I want to know how I can get the player to move freely until he crashes into a wall or any other Champion from the scene.

Like the game 2048, where the squares advance in a straight line and only stop when they collide on the wall or other pieces.

Below is the part of the code that declares the movement. What changes must I make to leave the movement as I quoted above?

//Co-routine for moving units from one space to next, takes a parameter end to specify where to move to.
protected IEnumerator SmoothMovement (Vector3 end)
{
    //Calculate the remaining distance to move based on the square magnitude of the difference between currente position and end parameter.
    //Square magnitude is used instead of magnitude because it's computationally cheaper.
    float sqrRemainingDistance = (transform.position - end).sqrMagnitude;
}

//While that distance is greater than a very small amount (Epsilon, almost zero):
while(sqrRemainingDistance > float.Epsilon)
{
    //Find a new position proportionally closer to the end, based on the moveTime
    Vector3 newPosition = Vector3.MoveTowards(rb2d.position, end, inverseMoveTime * Time.deltaTime);

    //Call MovePosition on attached Rigidbody2D and move it to the calculated position.
    rb2d.MovePosition (newPosition);

    //Recalculate the remaining distance after moving.
    sqrRemainingDistance = (transform.position - end).sqrMagnitude;

    //Return and loop until sqrRemainingDistance is close enough to zero to end the function
    yield return null;
}

• If easy to understand the question, this code has been provided by Unity and can be downloaded here.

• If it is not possible or impossible to change the code provided, also accepted in a code isolated from the game, since my goal is to understand this mechanics.