linked list (add to end and beginning, and looking for cycles based on Floyd's algorithm), C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
             Console.WriteLine("Add First:");
        LinkedList myList1 = new LinkedList();
        //myList1.initilizeTheList();
        myList1.AddFirst("Hello");
        myList1.AddFirst("Magical");
        myList1.AddFirst("World");
        myList1.printAllNodes();

Console.WriteLine();

Console.WriteLine("Add Last:");
        LinkedList myList2 = new LinkedList();
        //myList2.initilizeTheList();
        myList2.AddLast("Hello");
        myList2.AddLast("Magical");
        myList2.AddLast("World");
        myList2.printAllNodes();

bool hasCycle = myList2.HasCycle();

Console.WriteLine("myList2 " + ((hasCycle == true) ? "has a cycle" : "has no cycle"));
        Console.ReadLine();
        }
        
      
public class Node
{
    public Node next;
    public Object data;
}

public class LinkedList
{
    Node head;
    Node tail;

public void printAllNodes()
    {
        Node current = head;
        while (current != null)
        {
            Console.WriteLine(current.data);
            current = current.next;
        }
    }

public void AddFirst(Object data)
    {
        Node toAdd = new Node();
        if (tail == null && head == null) //empty list
        {
            head = toAdd;
            tail = toAdd;

}
        else
        {
            toAdd.next = head;
            head = toAdd;
        }
        toAdd.data = data;

}

public void AddLast(Object data)
    {

Node toAdd = new Node();

if (tail == null && head == null) //empty list
        {
            head = toAdd;
            tail = toAdd;

}
        else
        {
            tail.next = toAdd;
            tail = toAdd;
        }
        toAdd.data = data;
    }

public bool HasCycle()
    {
        Node slowRabbit;
        Node fastRabbit;
        if (head == null) return false;
        if (head.next == null) return false;
        if (head.next.next == null) return false;

slowRabbit = head;
        fastRabbit = slowRabbit.next;
        while (fastRabbit.next != null)
        {
            if (slowRabbit == fastRabbit.next) return true;
            else
            {
                slowRabbit = slowRabbit.next;
                if (fastRabbit.next != null)
                    if (fastRabbit.next.next != null)
                    {
                        fastRabbit = fastRabbit.next.next;
                    }
                    else { return false; }
                else { return false; }
            }

}
        return false;
    }

}  
        
        
        
    }
}

Show compiler warnings [ + ] Show input
Compilation time: 0,12 sec, absolute running time: 10,01 sec, cpu time: 0,09 sec, average memory usage: 22 Mb, average nr of threads: 5

linked list (add to end and beginning, and looking for cycles based on...