static assertion failed: NO Q_OBJECT in the class with the signal

I try to connect two classes and this error marks me, I want to connect the signal void puntaje (int )of duGRaphicsscene.hwith that slot void mostrar_puntos (int puntos) of game.hthese are my classes:

dugraphicsscene.h

    #ifndef DUGRAPHICSSCENE_H
    #define DUGRAPHICSSCENE_H

#include <QObject>
#include <QGraphicsScene>

class DuThreadTimer;
class DuBallItem;
class DuPlatformItem;
class game;

class DuGraphicsScene : public QGraphicsScene
{


public:
    DuGraphicsScene(QObject *parent = nullptr);
    void startScene();
    void stopScene();
protected:
    void keyPressEvent(QKeyEvent *event);
    void keyReleaseEvent(QKeyEvent *event);
private:

    void createObjects();
    void configureObjects();
    void connectObjects();
    void uodateScene();
    void checkCollitions();

    DuThreadTimer *mThreadTimer;
    DuBallItem *mBallItem;
    DuPlatformItem *mPlatformItem;
    game *obj_game;
    int puntos_niv = 0;
    int puntos = 0;
    int nivel = 1;

    signals:
    
        void puntaje(int );
    
    
    };

game.h:

#ifndef GAME_H
#define GAME_H

#include <QMainWindow>
#include "dugraphicsscene.h"

namespace Ui {
class game;
}

class DuArkanoid;
class game : public QMainWindow
{
    Q_OBJECT

public:
    explicit game(QWidget *parent = nullptr);
    ~game();

    bool IF_juego=false;

private slots:
    void on_actionIniciar_juego_triggered();

    void on_actionquitar_triggered();

    void on_bt_IFJuego_clicked();

public slots:
    void mostrar_puntos(int puntos);

signals:
    void most_vent(int);
private:
    Ui::game *ui;
    DuArkanoid *mArkanoid;

};

#endif // GAME_H

this is the dugraphicsscene.cpp, where I make the connection and send the signalemit puntaje(puntos)

#include "dugraphicsscene.h"
#include "duGlobalDefines.h"
#include "duthreadtimer.h"
#include "duballitem.h"
#include "duplatformitem.h"
#include "duutil.h"
#include "Comunes.h"
#include "game.h"
#include <QtDebug>
#include <QKeyEvent>


DuGraphicsScene::DuGraphicsScene(QObject *parent)
    :QGraphicsScene(0.0, 0.0, XSIZE,YSIZE, parent)
{
    createObjects();
    configureObjects();
    connectObjects();

}

void DuGraphicsScene::startScene()
{
    mThreadTimer->start();
}

void DuGraphicsScene::stopScene()
{
    mThreadTimer->terminate();
}

void DuGraphicsScene::keyPressEvent(QKeyEvent *event)
{
    mPlatformItem->move(event->key());
}

void DuGraphicsScene::keyReleaseEvent(QKeyEvent *event)
{
    event->accept();
}

void DuGraphicsScene::createObjects()
{
    mThreadTimer= new DuThreadTimer(MILISECONDS,this);
    mBallItem = new DuBallItem(XBALL+100,YBALL,WBALL,HBALL,VXBALL,VYBALL);
    mPlatformItem = new DuPlatformItem(XPLATFORM, YPLATFORM,WPLATFORM,HPLATFORM,VXPLATFORM,VYPLATFORM );
    obj_game = new game;
}

void DuGraphicsScene::configureObjects()
{
    addItem(mBallItem);
    addItem(mPlatformItem);
    addRect(0.0,0.0,XSIZE,YSIZE,QPen(QColor(Qt::black)));
}

void DuGraphicsScene::connectObjects()
{
    connect(mThreadTimer,&DuThreadTimer::timeOut,this,&DuGraphicsScene::uodateScene);
    connect(this,&DuGraphicsScene::puntaje,obj_game, &game::mostrar_puntos);

}

void DuGraphicsScene::uodateScene()
{

    for(int k=0;k<nivel;k++)
    {
        mBallItem->move();
    }


    if(mBallItem->collidesWithItem(mPlatformItem))//colision con item
    {
        puntos  +=  200;
        puntos_niv +=200;
        //qDebug()<<puntos;
        checkCollitions();
        emit puntaje(puntos);
        if(puntos_niv>=1000)
        {
            puntos_niv=0;
            nivel++;
            qDebug()<<nivel;

        }

    }
    update();
}

and this is the game.cpp where I display the points withui->lbl_puntos->setText(QString::number( puntos));

#include "game.h"
#include "ui_game.h"
#include "duakanoid.h"
#include <QGraphicsItem>
#include <QDebug>
#include<QApplication>

game::game(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::game)
{
    ui->setupUi(this);
    mArkanoid = new DuArkanoid(ui->graphicsView,this);
    //setCentralWidget(ui->graphicsView);


    ui->graphicsView->setBackgroundBrush(QPixmap("C:/Users/SNK93/Documents/Interfaz_Museo/resources/img/fondo_juego.png"));


}

game::~game()
{
    delete ui;
}

void game::on_actionIniciar_juego_triggered()
{

    mArkanoid->startGame();
}

void game::on_actionquitar_triggered()
{
    mArkanoid->stopGame();
    close();
}

void game::mostrar_puntos(int puntos)
{

    qDebug()<<puntos;
    ui->lbl_puntos->setText(QString::number( puntos));
}


void game::on_bt_IFJuego_clicked()
{
    if(IF_juego == false)
    {
        mArkanoid->startGame();
        ui->bt_IFJuego->setText("Detener");
        IF_juego=true;
    }
    else
    {
        mArkanoid->stopGame();
        ui->bt_IFJuego->setText("Iniciar");
        IF_juego=false;
        emit most_vent(3);
    }
}

but it ends up showing me this error:

C:\Qt\5.15.1\mingw81_64\include\QtCore\qglobal.h:121: error: static assertion failed: No Q_OBJECT in the class with the signal
    In file included from C:/Qt/5.15.1/mingw81_64/include/QtCore/qnamespace.h:43,
                     from C:/Qt/5.15.1/mingw81_64/include/QtCore/qobjectdefs.h:48,
                     from C:/Qt/5.15.1/mingw81_64/include/QtCore/qobject.h:46,
                     from C:/Qt/5.15.1/mingw81_64/include/QtCore/QObject:1,
                     from ..\Interfaz_Museo\dugraphicsscene.h:4,
                     from ..\Interfaz_Museo\dugraphicsscene.cpp:1:
    C:/Qt/5.15.1/mingw81_64/include/QtCore/qobject.h: In instantiation of 'static QMetaObject::Connection QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const typename QtPrivate::FunctionPointer<Func2>::Object*, Func2, Qt::ConnectionType) [with Func1 = void (DuGraphicsScene::*)(int); Func2 = void (game::*)(int); typename QtPrivate::FunctionPointer<Func>::Object = DuGraphicsScene; typename QtPrivate::FunctionPointer<Func2>::Object = game]':
    ..\Interfaz_Museo\dugraphicsscene.cpp:60:75:   required from here
    C:/Qt/5.15.1/mingw81_64/include/QtCore/qglobal.h:121:63: error: static assertion failed: No Q_OBJECT in the class with the signal
     #  define Q_STATIC_ASSERT_X(Condition, Message) static_assert(bool(Condition), Message)
                                                                   ^~~~~~~~~~~~~~~
    C:/Qt/5.15.1/mingw81_64/include/QtCore/qobject.h:249:9: note: in expansion of macro 'Q_STATIC_ASSERT_X'
             Q_STATIC_ASSERT_X(QtPrivate::HasQ_OBJECT_Macro<typename SignalType::Object>::Value,
             ^~~~~~~~~~~~~~~~~