A simple system to rewind time like in Prince of Persia

ICanRewind.cs

// Source : https://www.twitch.tv/videos/519292916?filter=all&sort=time
#region Author
/////////////////////////////////////////
//   RAPHAËL DAUMAS --> ICanRewind
//   https://raphdaumas.wixsite.com/portfolio
//   https://github.com/Marsgames
/////////////////////////////////////////
#endregion

public interface ICanRewind
{
    #region Unity's functions
    #endregion Unity's functions

    ///////////////////////////////////////////////////////////

    #region Functions
    void Rewind();
    void Record();
    #endregion Functions

    ///////////////////////////////////////////////////////////

    #region Accessors
    #endregion Accessors
}

Player.cs

#region Author
/////////////////////////////////////////
//   RAPHAËL DAUMAS --> Player
//   https://raphdaumas.wixsite.com/portfolio
//   https://github.com/Marsgames
/////////////////////////////////////////
#endregion
using UnityEngine;
using System.Collections.Generic;

[RequireComponent(typeof(Rigidbody2D))]
public class Player : MonoBehaviour, ICanRewind
{
    #region Variables
    [SerializeField] private float jumpVelocity = 5;
    [SerializeField] private float fallOffMultiplier = 2.5f;
    [SerializeField] private float lowJumpMultiplier = 2;

    private Rigidbody2D rigidbody;
    private Stack<Instant> instants = new Stack<Instant>();
    #endregion Variables

    ///////////////////////////////////////////////////////////

    #region Unity's functions
    private void Start()
    {
        TimeManager.Instance.SetRewindable(this);

        rigidbody = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        Move();
    }
    #endregion Unity's functions

    ///////////////////////////////////////////////////////////

    #region Functions
    private void Move()
    {
        if (Input.GetKey(KeyCode.Q))
        {
            transform.position += Vector3.left * .1f;
        }

        if (Input.GetKey(KeyCode.D))
        {
            transform.position += Vector3.right * .1f;
        }

        Jump(KeyCode.Space);
    }

    /// <summary>
    /// Function to jump like in Mario (long press jumps higher than short press)
    /// </summary>
    /// <param name="jumpButton">Jump button.</param>
    private void Jump(KeyCode jumpButton)
    {
        if (Input.GetKeyDown(jumpButton))
        {
            rigidbody.velocity = Vector2.up * jumpVelocity;
        }

        if (rigidbody.velocity.y < 0)
        {
            rigidbody.velocity += Vector2.up * (Physics2D.gravity.y * rigidbody.gravityScale) * (fallOffMultiplier - 1) * Time.deltaTime;
        }
        else if (rigidbody.velocity.y > 0 && !Input.GetKey(jumpButton))
        {
            rigidbody.velocity += Vector2.up * (Physics2D.gravity.y * rigidbody.gravityScale) * (lowJumpMultiplier - 1) * Time.deltaTime;
        }
    }

    /// <summary>
    /// Set the value back to rewind time
    /// </summary>
    public void Rewind()
    {
        Instant t;

        if (instants.Count > 1)
        {
            // Pop remove element from stack when we use it
            t = instants.Pop();
        }
        else
        {
            // Peek only get element
            t = instants.Peek();
        }

        transform.position = t.GetPosition();
        rigidbody.velocity = t.GetVelocity();
    }

    /// <summary>
    /// Save everything we want to save for the player
    /// </summary>
    public void Record()
    {
        Instant t = new Instant(transform.position, rigidbody.velocity);
        instants.Push(t);
    }
    #endregion Functions

    ///////////////////////////////////////////////////////////

    #region Accessors
    #endregion Accessors

    #region Struct
    /// <summary>
    /// Structure that will contains all informations we wants to record for this class
    /// </summary>
    struct Instant
    {
        private Vector2 instantPosition;
        private Vector2 instantVelocity;

        public Instant(Vector2 position, Vector2 velocity)
        {
            instantPosition = position;
            instantVelocity = velocity;
        }

        public Vector2 GetPosition()
        {
            return instantPosition;
        }

        public Vector2 GetVelocity()
        {
            return instantVelocity;
        }
    }
    #endregion Struct
}

TimeManager.cs

// Source : https://www.twitch.tv/videos/519292916?filter=all&sort=time
#region Author
/////////////////////////////////////////
//   RAPHAËL DAUMAS --> TimeManager
//   https://raphdaumas.wixsite.com/portfolio
//   https://github.com/Marsgames
/////////////////////////////////////////
#endregion
using System.Collections.Generic;
using UnityEngine;

public class TimeManager : MonoBehaviour
{
    #region Variables
    [HideInInspector] public static TimeManager Instance { get; private set; }

    private bool isRewinding;
    private List<ICanRewind> rewindables = new List<ICanRewind>();
    #endregion Variables

    ///////////////////////////////////////////////////////////

    #region Unity's functions
    private void Awake()
    {
        if (!Instance)
        {
            Instance = this;
        }
        else if (this != Instance)
        {
            Destroy(gameObject);
        }

        DontDestroyOnLoad(this);
    }

    private void Update()
    {
        RewindButton(KeyCode.S);
    }

    /// <summary>
    /// Record/Rewind time when isRewinding is true
    /// Maybe it should be dirrectly into RewindButton function ?
    /// </summary>
    private void FixedUpdate()
    {
        foreach (ICanRewind obj in rewindables)
        {
            if (isRewinding)
            {
                obj.Rewind();
            }
            else
            {
                obj.Record();
            }
        }
    }
    #endregion Unity's functions

    ///////////////////////////////////////////////////////////

    #region Functions
    /// <summary>
    /// Set isRewinding when rewindButton is pressed
    /// </summary>
    /// <param name="rewindButton">Rewind button.</param>
    private void RewindButton(KeyCode rewindButton)
    {
        if (Input.GetKeyDown(rewindButton))
        {
            isRewinding = true;
        }
        else if (Input.GetKeyUp(rewindButton))
        {
            isRewinding = false;
        }
    }
    #endregion Functions

    ///////////////////////////////////////////////////////////

    #region Accessors
    /// <summary>
    /// Used for objects implementing ICanRewind to call there Record/Rewind functions
    /// </summary>
    /// <param name="obj">Object.</param>
    public void SetRewindable(ICanRewind obj)
    {
        rewindables.Add(obj);
    }
    #endregion Accessors
}