The PlayerController component from my game, BulletFish!

PlayerController.cs

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

public class PlayerController : MonoBehaviour 
{
    [HideInInspector] public GameController gc; // reference to the scene's gamemanager object's gamecontroller component
    [HideInInspector] public ParticleSystem Bubbles; // reference to the scene's gamemanager object's gamecontroller component
    public GameObject playerGun; // reference to Player's gun

    public float moveForce = 11f;
    public float jumpForce = 750f;
    public float jumpSpeed = 0.5f;
    
    public float minJumpTime = 1.0f;
    private float jumpTimerCountdown;

    private Rigidbody2D rb;
    private Collider2D c;
    private SpriteRenderer sr;
    private HealthPoints hp;
    private Animator anim;

    private float inputX = 0f;
    private float inputFall = 0f;
    
    [HideInInspector] public bool facingLeft = false;
    public bool grounded = true;

    private bool alive = true;
    [HideInInspector] public bool takingDamage = false;

    public Transform foot;

    public float rayDist = 1.0f;

    void Awake () 
    {
        gc = GameObject.FindGameObjectWithTag("GameController").GetComponent<GameController>();
        rb = GetComponent<Rigidbody2D>();
        c = GetComponent<Collider2D>();
        sr = GetComponent<SpriteRenderer>();
        hp = GetComponent<HealthPoints>();
        anim = GetComponent<Animator>();

        Bubbles = GetComponentInChildren<ParticleSystem>();

        jumpTimerCountdown = 0f;
    }

    void Start()
    { 
    	gc.UpdateHPDisplay(hp.HP);
    }
	
	void Update () 
	{
        if (hp.isZero)
        {
            alive = false;
            sr.color = Color.black;
            anim.enabled = false;
            Bubbles.Stop();
            playerGun.GetComponent<GunController>().enabled = false;
        } else if (takingDamage)
		{
			takingDamage = false;
		}

        if (!grounded)
        {
            anim.SetBool("isFalling", true);
        } else
        {
            anim.SetBool("isFalling", false);
        }

        // Cast Ray to see if we're grounded
        Debug.DrawLine(transform.position, new Vector2(transform.position.x, transform.position.y) + (rayDist * Vector2.down), Color.red);
        if (Physics2D.Raycast(transform.position, Vector2.down, rayDist).collider.gameObject.tag == "Floor")
        {
            grounded = true;
            Bubbles.Stop();
        }

        if (transform.position.y > gc.StageTop.transform.position.y)
        {
            transform.position = new Vector3(transform.position.x, gc.StageTop.transform.position.y, transform.position.z);
            rb.velocity = new Vector2(rb.velocity.x, 0);
        }

        if (alive)
        {
            Move();
        } else
        {
            gc.GameOver();
        }
	}

    void OnCollisionEnter2D(Collision2D coll)
    {
        if (coll.gameObject.tag == "Floor" && (coll.gameObject.transform.position.y <= foot.position.y || rb.velocity.y < 0))
        {
            grounded = true;    // we're touching the floor
            Bubbles.Stop();
        }

        if (coll.gameObject.tag == "Enemy" && !coll.gameObject.GetComponent<HealthPoints>().isZero)
        {
            EnemyController ec = coll.gameObject.GetComponent<EnemyController>();
            hp.SendMessage("ApplyDamage", ec.damageOnContact);
            takingDamage = true;
            coll.gameObject.GetComponent<ColliderManager>().DisableColliderTemporarily();
            AudioController.instance.PlaySound("Impact1");
        }

        if (coll.gameObject.tag == "Bomb")
        {
            Bomb bomb = coll.gameObject.GetComponent<Bomb>();
            hp.SendMessage("ApplyDamage", bomb.damageOnContact);
            takingDamage = true;
            bomb.Explode();
        }
    }

    void OnCollisionStay2D(Collision2D coll)
    {
        if (coll.gameObject.tag == "Floor" && (coll.gameObject.transform.position.y <= foot.position.y))
        {
           grounded = true; // we're touching the floor
           Bubbles.Stop();
        }
    }

    void OnCollisionExit2D(Collision2D coll)
    {
        if (coll.gameObject.tag == "Floor" )
        {
            grounded = false; // we're no longer touching the floor
        }
    }

    void OnTriggerEnter2D(Collider2D coll)
    {
        if (coll.gameObject.tag == "PickupPoints" && !hp.isZero)
        {
            PickupPoints Pts = coll.gameObject.GetComponent<PickupPoints>();
            gc.addPoints(Pts.value);
            Destroy(coll.gameObject);
            AudioController.instance.PlaySound("Pickup0");
        }
    }


    private void Move()
    {
        Debug.Log("Y Velocity: " + rb.velocity.y);

        // obtain movement input
        inputX = Input.GetAxisRaw("Horizontal");
        // Update Animator State
        if (Mathf.Abs(inputX) > 0)
        {
            anim.SetBool("hasXInput", true);
        } else
        {
            anim.SetBool("hasXInput", false);
        }

        inputFall = -(Mathf.Abs(Input.GetAxisRaw("Vertical")));

        // Apply X and Y movement if valid input exists
        float XForce = moveForce * inputX;
        rb.velocity = new Vector2(XForce, rb.velocity.y);

        if (grounded && Input.GetButtonDown("Jump")) // Correct situation for a new jump?
        {
            grounded = false;
            AudioController.instance.PlaySound("Jump0");    // Play JUMP sound
            if (Bubbles.isStopped) Bubbles.Play();          // Start Bubbles
            jumpTimerCountdown = minJumpTime;
        }

        if (jumpTimerCountdown > 0) // Engaged in stage one jump
        {
            rb.velocity = new Vector2(XForce, jumpSpeed);
            jumpTimerCountdown -= Time.deltaTime;
            if (jumpTimerCountdown <= 0)    // End stage one jump  
            {
                rb.velocity = new Vector2(XForce, 0);
                rb.AddForce(new Vector2(0, jumpForce)); // Little boost to make mock gravity effect 
            }
        }
        
        if (!grounded) if (Bubbles.isStopped) Bubbles.Play();

        // correct Sprite based on direction of movement
        if (XForce < 0 && !facingLeft && Time.timeScale > 0)
        {
            Flip();
            facingLeft = true;
        }
        else if (XForce > 0 && facingLeft && Time.timeScale > 0)
        {
            Flip();
            facingLeft = false;
        }
    }

    // Flip SpriteRenderer in the X axis.
    private void Flip()
    {
        if (sr.flipX) { sr.flipX = false; } else { sr.flipX = true; }
    }
}