A short script for making objects appear in Unity's Roll-a-Ball - works with the Input System

Appear.cs

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

public class Appear : MonoBehaviour
{

    public GameObject ball;
    public int count; // number of cubes needed to make this object appear

    private PlayerController player;
    private MeshRenderer mesh;

    // Start sets up the components so that they recognize each other
    // and turns off mesh renderer so that components aren't visible
    void Start()
    {
        player = ball.GetComponent<PlayerController>();
        mesh = this.GetComponent<MeshRenderer>();
        mesh.enabled = false;
    }

    // Turns renderer on if # of cubes collected equals public count
    void LateUpdate()
    {
        if (player.getCount() == count && !mesh.enabled)
        {
            mesh.enabled = true;
        }
    }
}

/* NOTE: Need to add this function to player controller script:
   public int getCount()
    {
        return count;
    }
*/