This is the code to make our player come back at it's start position when he lost so let's explain it:

Vector2 startPosition;

private void Start()
{
    startPosition = transform.position;
}

void playerLost()
{
    transform.position = startPosition;
    rb.velocity = Vector2.zero;
    Debug.Log("You lost");
}

1. Vector2 startPosition: this line declares a variable startPosition of type Vector2. It will store the initial position of the player;

2. private void Start(): this method is called when the game starts. It assigns the current position of the player to startPosition, effectively saving the starting position;

3. void playerLost(): this custom method is triggered when the player loses. It resets the player's position to the saved startPosition, stops any movement by setting velocity to zero, and logs a message "You lost" to the console.

void playerLost()
{
    transform.position = startPosition;

    rb.velocity = Vector2.zero;

    Debug.Log("You lost");
}