MainViewModel2.cs

    internal class MainViewModel : NotifyPropertyChangedBase
    {
        private Simulator.GameState _state;

        public MainViewModel()
        {
            ResetCommand = new ActionCommand(Reset);

            Reset();
        }

        public ActionCommand ResetCommand { get; }

        private void Reset()
        {
            World.World world = WorldGeneration.makeDefaultWorld();
            State = new Simulator.GameState(world, Simulator.SimulationState.Simulating, 30);
        }

        public Simulator.GameState State
        {
            get => _state;
            set
            {
                _state = value;
                OnPropertyChanged(nameof(TextGrid));
                OnPropertyChanged(nameof(GameStatusText));
                OnPropertyChanged(nameof(TurnsLeftText));
            }
        }
        
        // Other properties largely unchanged...
    }
}