duck

public class Player : MonoBehaviour {

    float xMove = 0;
    float yMove = 0;
    float gravity = 0.1f;

    void FixedUpdate() {
        yMove += gravity;
    }

    void Update() {

        xMove = Input.GetAxis("Horizontal");

        if (onGround && Input.GetKeyDown(KeyCode.Space)) {
            yMove = -5;
        }

        transform.Translate(new Vector3(xMove,yMove,0)* Time.deltaTime);
    }