unity 2d look at mouse code example

Example 1: Point to mouse 2D Unity

Vector3 difference = Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position;
        difference.Normalize();
        float rotation_z = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
        transform.rotation = Quaternion.Euler(0f, 0f, rotation_z + offset);

Example 2: unity 2d looka tt mouse

void Update() {
     Vector3 dir = Input.mousePosition - Camera.main.WorldToScreenPoint(transform.position);
     float angle = Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg;
     transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);