Player.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Player : MonoBehaviour
{
    [SerializeField]
    private bool _isTripleShotActive = false;
    [SerializeField]
    private float _speed = 3.5f;
    [SerializeField]
    private GameObject _laserPrefab;
    [SerializeField]
    private GameObject _tripleLaserPrefab;
    [SerializeField]
    private float _firerate = .15f;
    private float _canFire = -1f;
    [SerializeField]
    private int _lives = 3;
    private SpawnManager _spawnManager;





    // Start is called before the first frame update
    void Start()
    {
        //make current position = (0,0,0)
        transform.position = new Vector3(0, 0, 0);
        _spawnManager = GameObject.Find("Spawn_Manager").GetComponent<SpawnManager>();
        if (_spawnManager == null)
        {
            Debug.LogError("Spawn Manager is NULL");
        }
    }

    // Update is called once per frame
    void Update()
    {
        calculateMovement();
        if (Input.GetKeyDown(KeyCode.Space) && Time.time > _canFire)
        {
            fireLaser();
        }

    }
    void calculateMovement()
    {
        //Base movement
        float horizontalInput = Input.GetAxis("Horizontal");
        float verticalInput = Input.GetAxis("Vertical");
        transform.Translate(new Vector3(horizontalInput, verticalInput, 0) * _speed * Time.deltaTime);

        // Block player from leaving game screen.
        if (transform.position.y >= 0) // y movement
        {
            transform.position = new Vector3(transform.position.x, 0, transform.position.z);
        }
        else if (transform.position.y <= -3.8f)
        {
            transform.position = new Vector3(transform.position.x, -3.8f, transform.position.z);
        }
        //Alternate solution for above, won't work for looping around
        // transform.position = new Vector3(transform.position.x,Mathf.Clamp(transform.position.y,-3.8f, 0),0);


        if (transform.position.x < -11.3f) // x movement
        {
            transform.position = new Vector3(11.3f, transform.position.y, transform.position.z);
        }
        else if (transform.position.x > 11.3f)
        {
            transform.position = new Vector3(-11.3f, transform.position.y, transform.position.z);
        }

    }
    void fireLaser()
    {

        if (_isTripleShotActive==true)
        {
            Instantiate(_tripleLaserPrefab, transform.position, Quaternion.identity);
        }
        else
        {
            Instantiate(_laserPrefab, transform.position + new Vector3(0, 1.05f, 0), Quaternion.identity);
        }
        _canFire = Time.time + _firerate;

    }

    public void Damage()
    {
        _lives--;
        if (_lives <=0)
        {
            _spawnManager.OnPlayerDeath();
            Destroy(this.gameObject);
        }
    }
    public void TripleShotActive()
    {
        _isTripleShotActive = true;
        Debug.Log("Powerup request received");
        StartCoroutine(TripleShotPowerDownRoutine());
    }
    IEnumerator TripleShotPowerDownRoutine()
    {
        yield return new WaitForSeconds(5.0f);
        _isTripleShotActive = false;
    }
}