Moving a player through a textual maze

Question

I did this to practice a bit without thinking about optimization due to simplicity of this progam.

It's a "maze game", the player is P and can step into the M by pressing Arrows on the Keyboard.

At the start a txt with the current level is loaded.

Anyway, how would you optimize this code?

I was thinking about making the string builder static.

Input file:

##############################
#PMMM#######MMM#MMM###########
####M#######M#M#M#M###########
#MMMMMMMMMMMM#MMM#M###########
#M####M###########M###########
#M####M###########M###########
#M####M#########MMM###########
#M####M#########M#############
#M####M#########M#############
#M####M#########M#############
#M####M#########M#############
#M####M#########M#############
#M####M#####MMMMM#############
#M####M####MM#################
#M###MM####M##################
#M##MM#####M##################
#M##M#MMMMMM##################
#M##M#E#######################

Code:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Reflection;

namespace test
{
    class Program
    {
        // P - player
        // ^ - percurred
        // M - walkable maze
        // # - not walkable maze
        // E - end
        static List<string> Maze = new List<string>();
        static int PlayerX = 0;
        static int PlayerY = 0;
        static ConsoleKeyInfo KeyInfo;
        static void Main(string[] args)
        {
            Maze = File.ReadAllLines("maze.txt").ToList();
            UpdateOutput();
            while (true)
            {
                KeyInfo = Console.ReadKey();
                try
                {
                    WaitForInput();
                }
                catch
                {
                    Console.Clear();
                    Console.WriteLine("Lose!");
                    Console.ReadLine();
                    System.Diagnostics.Process.Start(Assembly.GetExecutingAssembly().Location);
                    Environment.Exit(0);
                }
            }
        }

        private static void UpdateOutput()
        {
            Console.Clear();
            for (int i = 0; i < Maze.Count; i++)
            {
                if (Maze[i].Contains("P"))
                {
                    PlayerY = i;
                    PlayerX = Maze[i].IndexOf("P");
                }
                Console.WriteLine(Maze[i]);
            }
        }

        private static void End()
        {
            Console.Clear();
            Console.WriteLine("Victory!");
            Console.ReadLine();
            System.Diagnostics.Process.Start(Assembly.GetExecutingAssembly().Location);
            Environment.Exit(0);
        }

        private static void WaitForInput()
        {
            if (KeyInfo.Key == ConsoleKey.DownArrow)
            {
                if (Maze[PlayerY + 1][PlayerX] == 'M')
                {
                    StringBuilder sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX] = '^';
                    Maze[PlayerY] = sb.ToString();
                    sb = new StringBuilder(Maze[PlayerY + 1]);
                    sb[PlayerX] = 'P';
                    Maze[PlayerY + 1] = sb.ToString();
                    UpdateOutput();
                }
                else if (Maze[PlayerY + 1][PlayerX] == 'E')
                {
                    End();
                }
            }

            if (KeyInfo.Key == ConsoleKey.UpArrow)
            {
                if (Maze[PlayerY - 1][PlayerX] == 'M')
                {
                    StringBuilder sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX] = '^';
                    Maze[PlayerY] = sb.ToString();
                    sb = new StringBuilder(Maze[PlayerY - 1]);
                    sb[PlayerX] = 'P';
                    Maze[PlayerY - 1] = sb.ToString();
                    UpdateOutput();
                }
                else if (Maze[PlayerY - 1][PlayerX] == 'E')
                {
                    End();
                }
            }

            if (KeyInfo.Key == ConsoleKey.RightArrow)
            {
                if (Maze[PlayerY][PlayerX + 1] == 'M')
                {
                    StringBuilder sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX] = '^';
                    Maze[PlayerY] = sb.ToString();
                    sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX + 1] = 'P';
                    Maze[PlayerY] = sb.ToString();
                    UpdateOutput();
                }
                else if (Maze[PlayerY][PlayerX + 1] == 'E')
                {
                    End();
                }
            }

            if (KeyInfo.Key == ConsoleKey.LeftArrow)
            {
                if (Maze[PlayerY][PlayerX - 1] == 'M')
                {
                    StringBuilder sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX] = '^';
                    Maze[PlayerY] = sb.ToString();
                    sb = new StringBuilder(Maze[PlayerY]);
                    sb[PlayerX - 1] = 'P';
                    Maze[PlayerY] = sb.ToString();
                    UpdateOutput();
                }
                else if (Maze[PlayerY][PlayerX - 1] == 'E')
                {
                    End();
                }
            }
        }

    }

}