Program.cs

using System.Diagnostics;
using Windows.Win32;
using Windows.Win32.Foundation;
using Windows.Win32.UI.WindowsAndMessaging;

namespace GameAwaiter
{
    public static class Program
    {

        public static int Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.WriteLine("Path not set");
                if (OperatingSystem.IsWindowsVersionAtLeast(10, 0, 10240, 0))
                    PInvoke.MessageBox(new HWND(0), "Path not set", "GameAwaiter", MESSAGEBOX_STYLE.MB_OK);
                else
                {
                    Console.WriteLine("Path not set");
                    Console.ReadKey();
                }
                return -1;
            }

            var app = args[0];

            if (!File.Exists(app))
            {
                if (OperatingSystem.IsWindowsVersionAtLeast(10, 0, 10240, 0))
                    PInvoke.MessageBox(new HWND(0), $"Executable not found at \"{app}\"", "GameAwaiter", MESSAGEBOX_STYLE.MB_OK);
                else
                {
                    Console.WriteLine($"Executable not found at \"{app}\"");
                    Console.ReadKey();
                }
                return -1;
            }

            var delay = args.Length >= 2 ? int.Parse(args[1]) : 5000;

            if (WaitForNewProcess(app))
                return 0;

            Console.WriteLine($"Starting: {app}");

            Thread.Sleep(delay);

            using (var p = new Process())
            {
                p.StartInfo.Verb = "runas";
                p.StartInfo.FileName = app;
                p.StartInfo.WorkingDirectory = Path.GetDirectoryName(app);
                p.StartInfo.UseShellExecute = true;
                p.Start();
                Console.WriteLine($"PID: {p.Id}");
                p.WaitForExit();
            }

            WaitForNewProcess(app);

            return 0;
        }

        private static bool WaitForNewProcess(string app)
        {
            using (var process1 = GetNewProcess(app))
                if (process1 == null)
                    return false;
            while (true)
            {
                using (var process2 = GetNewProcess(app))
                {
                    if (process2 == null)
                        return true;
                    Console.WriteLine($"PID: {process2.Id}");
                    process2.WaitForExit();
                }
            }
        }

        private static Process? GetNewProcess(string app)
        {
            var processes = Process.GetProcessesByName(Path.GetFileNameWithoutExtension(app));
            if (processes.Length != 1)
            {
                foreach (var p in processes)
                    p.Dispose();
                return null;
            }
            return processes[0];
        }
    }
}