make a platform go up and down with script

Unity Engine
,
1

Hey!

Im making a platformer and i want to make a moving platform. I know how to do it with animations, but i have to do an animation for every object so i got an script

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

public class PlatformMovement : MonoBehaviour
{
    public bool upordown = true; // true is up false is down;
    public float speed = 2;
    public Transform Platform;
    public int smallorbig = 0; // 0 is off 1 is small and 2 is big
    public float timetim = 3f;
    public float timetim2 = 3f;

    void Start()
    {
       
    }

  
    void Update()
    {
        if (smallorbig == 1)
        {

            timetim -= Time.deltaTime;
            if (timetim <= 0f)
            {

                transform.position += new Vector3(0, speed * Time.deltaTime, 0);
                upordown = true;

            }
            if (timetim > 0f)
            {
                transform.position += new Vector3(0, -speed * Time.deltaTime, 0);
            }
            if (timetim <= -3f)
            {
                timetim = timetim2;
            }

            }
       

        }
    }

and it moves it 1 time perfectly but at some point it sets the timetim to 4 so it starts moving more down than up and i dont want that my brain is starting to hurt so yeah in conclusion its a moving platform that works 1 time and then it sets the timer variable to 4 so it goes more down than up

2
3

it started to work when i changed the timertim = timertim2 to timertim = 3f;

4

You should consider renaming your variables to aid in comprehension of your code’s function.

For instance, upordown should probably be called goingUp

Nobody should be forced to work with timetim and timetim2. I would suggest a replacement but I have no idea what you intended, and I suspect in 7 more days neither will you.