I open ingame menu once and then my other keys not working

I am doing a Pong game. I made a panel which is ingame menu and set key C to open it.

       if (e.KeyCode == Keys.Escape)
        {
            Application.Exit();
        }

        if (e.KeyCode == Keys.Space)
        {
            piłka.Top = 50;
            piłka.Left = 50;
            speed_left = 4;
            speed_top = 4;
            pkt = 0;
            punkty_tb.Text = "0";
            timer1.Enabled = true;
            przegrana_tb.Visible = false;
        }

        if (e.KeyCode == Keys.C)
        {
          igmenu.Show();
          Cursor.Show();
          timer1.Enabled = false;
        }

In this menu I have button Resume

      private void playButton_Click(object sender, EventArgs e)
      {
        timer1.Enabled = true;
        igmenu.Hide();
        Cursor.Hide();
       }

When I resume my game, it works but the keys i set before are not working. I am begginer so I don't say my program is perfect. Thanks.