Android touch question

Hey Everybody!

So, I have been trying to figure out how to make a ship go up and down and side to side. Ive only been able to make it go side to side and straight forward, and I can't figure out why.

Here's some of the code

 if (Input.touches[0].phase == TouchPhase.Moved)
                 {
                     float x = Input.touches[0].deltaPosition.x * speed * Time.deltaTime;
                     float y = Input.touches[0].deltaPosition.y * speed * Time.deltaTime;
                     transform.Translate(Vector3(x, y, 0));
                 }
 

If you could help that would be great!