6.2 — Ground Checks: No Infinite Jumps

Compare against your own file rather than copying it. The gap is the raycast assignment: a point, a direction, a distance and a mask, in that order. This version assigns the result straight into the bool, because a RaycastHit2D converts to true or false on its own — writing .collider != null on the end is equally correct. What has to match is the shape: the answer is computed in exactly one place, every frame rather than stored when you land, and read by the jump before it fires.

// ------------------------------------------------------------------
//  REFERENCE FILE — Assets/Scripts/PlayerController.cs
//  Written to be read, not pasted. Build it with the walkthrough
//  above, one step at a time, then open this and compare.
//  If it is sitting in your project unchanged, that is the thing
//  to go and do now — the walkthrough is still above you.
// ------------------------------------------------------------------
using UnityEngine;

// PlayerController.cs at the end of 6.2 — everything from 1.4 through 6.1,
// plus the one question this script has never asked: am I standing on
// something? Every other line here TELLS the engine what to do. CheckGround()
// ASKS it something, and CheckJump() is the only line that acts on the answer.
public class PlayerController : MonoBehaviour
{
    [SerializeField] private float moveSpeed = 5f;
    [SerializeField] private float jumpForce = 7f;          // yours, from 6.1

    // Today's three knobs, all visible in the Inspector (1.3).
    [SerializeField] private Transform groundCheck;              // where the ray starts
    [SerializeField] private float groundCheckDistance = 0.1f;   // how far down it reaches
    [SerializeField] private LayerMask groundLayer;              // what it may notice

    private Rigidbody2D body;

    // The answer. In the class body, because the check writes it and the jump
    // reads it — and re-derived every frame, because nothing ever tells you it
    // changed.
    private bool isGrounded;

    void Start()
    {
        // Looked up once, never inside Update() — the rule from 1.6 and 2.2.
        body = GetComponent<Rigidbody2D>();
    }

    void Update()
    {
        // ... your input, movement, gravity and animation lines from
        // 1.4, 1.6, 2.2 and 6.1, unchanged and left out here ...

        CheckGround();   // ask
        CheckJump();     // act on the answer
        UpdateAnimation();
    }

    // The whole lesson. A ray from the point under your feet, one direction,
    // one distance, one mask — and the result assigned straight into the bool,
    // because a RaycastHit2D converts to true when it hit and false when it
    // did not. Nothing here moves anything: a question is not an action.
    void CheckGround()
    {
        isGrounded = Physics2D.Raycast(groundCheck.position, Vector2.down, groundCheckDistance, groundLayer);
    }

    // The jump from 6.1 with one term in front of it. Leave the term out and
    // the character can climb the sky.
    void CheckJump()
    {
        if (isGrounded && Input.GetKeyDown(KeyCode.Space))
        {
            body.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
        }
    }

    // The same three inputs the ray uses, drawn. Keep the Player selected in
    // the Hierarchy while you play, and watch this go red the frame you leave
    // the ground.
    private void OnDrawGizmosSelected()
    {
        if (groundCheck == null)
        {
            return;
        }

        Gizmos.color = isGrounded ? Color.green : Color.red;
        Gizmos.DrawLine(groundCheck.position, groundCheck.position + Vector3.down * groundCheckDistance);
    }

    // ... UpdateAnimation(), CheckAttack(), the pickups and the damage, unchanged ...
}

// Edit ▸ Project Settings ▸ Tags and Layers:
//   the first empty User Layer  =  Ground
//
// Inspector, on Assets/Prefabs/Player ▸ PlayerController:
//   Ground Check            =  GroundCheck   <- an empty child sitting on the
//                                               BOTTOM EDGE of your collider
//   Ground Check Distance   =  0.1           <- measured, not guessed
//   Ground Layer            =  Ground        <- Ground, and nothing else
//
// The layer goes on BOTH solid tilemaps under the cave's Grid — Collision and
// Cave Exit. The third one, No Collision, has no collider at all, so no ray can
// ever hit it whatever layer it is on.