Script for Unity to control the main character in an 2D platformer game

CharacterController2D.cs

//
//  CharacterController2D.cs
//
//  Created by Rigoberto Sáenz Imbacuán (https://linkedin.com/in/rsaenzi/)
//  Copyright © 2021. All rights reserved.
//

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

[RequireComponent(typeof(SpriteRenderer))]
[RequireComponent(typeof(Collider2D))]
[RequireComponent(typeof(Rigidbody2D))]
[RequireComponent(typeof(Animator))]

public class CharacterController2D : MonoBehaviour {

    [Tooltip("Horizontal motion speed in meters/seconds")]
    public float motionSpeed;

    [Tooltip("Jump force in newtons")]
    public float jumpForce;

    [Tooltip("Amount of coins the character has collected")]
    public int coins;

    [Tooltip("Key to move the character left")]
    public KeyCode keyLeft;

    [Tooltip("Key to move the character right")]
    public KeyCode keyRight;

    [Tooltip("Key to make the character jump")]
    public KeyCode keyJump;

    // This variable is used to prevent jump while in the air
    bool characterIsJumping = false;

    // Use this for initialization
    void Awake() {
        coins = 0;
    }

    // Update is called once per frame
    void Update() {

        // If 'keyRight' key is pressed, move the character left
        if (Input.GetKey(keyRight)) {

            // Move character to the right
            this.transform.Translate(Vector3.right * motionSpeed * Time.deltaTime, Space.Self);

            // Set IsRunning variable inside Animator to true, to enter to Running animation state
            this.gameObject.GetComponent<Animator>().SetBool("IsRunning", true);

            // Flip the gameobject to make the character look to the right
            this.gameObject.GetComponent<SpriteRenderer>().flipX = true;
        }

        // If 'keyLeft' key is pressed, move the character left
        if (Input.GetKey(keyLeft)) {

            // Move character to the left
            this.transform.Translate(Vector3.left * motionSpeed * Time.deltaTime, Space.Self);

            // Set IsRunning variable inside Animator to true, to enter to Running animation state
            this.gameObject.GetComponent<Animator>().SetBool("IsRunning", true);

            // Unflip the gameobject to make the character look to the left
            this.gameObject.GetComponent<SpriteRenderer>().flipX = false;
        }

        // If player release either 'keyLeft' or 'keyRight' keys...
        if (Input.GetKeyUp(keyLeft) || Input.GetKeyUp(keyRight)) {

            // Set IsRunning variable inside Animator to false, to exit from Running animation state
            this.gameObject.GetComponent<Animator>().SetBool("IsRunning", false);
        }

        // If 'keyJump' key is pressed, makes the character jump
        if (Input.GetKeyDown(keyJump) && characterIsJumping == false) {

            // Set this to true so we do not allow jumping while in the air
            characterIsJumping = true;

            // Applies a force to make the collider jump up
            this.gameObject.GetComponent<Rigidbody2D>().AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);

            // Set IsRunning variable inside Animator to true, to enter to Jumping animation state
            this.gameObject.GetComponent<Animator>().SetBool("IsJumping", true);
        }
    }

    // When character's collider touches another collider
    void OnCollisionEnter2D(Collision2D col) {

        // If character touches a platform...
        if (col.gameObject.tag == "Platform") {

            // Set this to false so the character can jump again
            characterIsJumping = false;

            // Set IsJumping variable inside Animator to false, to exit from Jumping animation state
            this.gameObject.GetComponent<Animator>().SetBool("IsJumping", false);
        }

        // If character touches a coin...
        if (col.gameObject.tag == "Coin") {

            // Drop the coin gameobject
            Destroy(col.gameObject);

            // Increase the amount of collected coins
            coins = coins + 1;

            // Display the amount of coins in a UI Text component
            GameObject.Find("Canvas/CoinCount").GetComponent<Text>().text = coins.ToString();

            // Play the audio fx for action "catch coin"
            // AudioPlayer.playSoundFX("AudioCoin");
        }
    }
}

/*
 * 
 * Related:
 * 
 *   AudioPlayer: Script for Unity to play/stop sound fx and music
 *   https://gist.github.com/rsaenzi/119357d38d9c7255adfa8e465d486d0c
 * 
 *   UINavigation: Script for Unity to load/unload UI screens
 *   https://gist.github.com/rsaenzi/95df01c056d352651a9143b13ce305fa
 * 
 *   LevelLoader: Script for Unity to load/unload levels
 *   https://gist.github.com/rsaenzi/33cfff7d20e62c6f229442f7c6a7aa90
 * 
 */