C# premikanje objekta istočasno

Delam ping pong igrico. Uspelo mi je narediti da ko sta tipki za premikanje pritisnjeni se oba objekta premikata, problem nastane ko en izmed igralcev tipko samo klikne-je ne drži, potem se drugemu igralcu plošček tudi ustavi čeprav še vedno drži tipko za premikanje.

Koda:

public void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            Keys up1 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_gor1.Text , true);
            Keys down1 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_dol1.Text , true);

            Keys up2 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_gor2.Text, true);
            Keys down2 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_dol2.Text, true);

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

            if(e.KeyCode == up1)
            {
                goup1 = true;
            }
            if (e.KeyCode == down1)
            {
                godown1 = true;
            }
            if (e.KeyCode == up2)
            {
                goup2 = true;
            }
            if (e.KeyCode == down2)
            {
                godown2 = true;
            }
            igra1();
        }

private void Form1_KeyUp(object sender, KeyEventArgs e)
        {
            Keys up1 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_gor1.Text, true);
            Keys down1 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_dol1.Text, true);

            Keys up2 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_gor2.Text, true);
            Keys down2 = (Keys)Enum.Parse(typeof(Keys), form1.p5_text_kontrole_dol2.Text, true);

            if (e.KeyCode == up1)
            {
                goup1 = false;
            }
            if (e.KeyCode == down1)
            {
                godown1 = false;
            }

            if (e.KeyCode == up2)
            {
                goup2 = false;
            }
            if (e.KeyCode == down2)
            {
                godown2 = false;
            }
            igra1();
        }

public void igra1()
        {
            if (goup1)
            {
                if (form1.p6_ploscek1.Top > form1.panel6_pongIgra.Top)
                    form1.p6_ploscek1.Top -= 15;
            }
            if (goup2)
            {
                if (form1.p6_ploscek2.Top > form1.panel6_pongIgra.Top)
                    form1.p6_ploscek2.Top -= 15;
            }
            if (godown1)
            {
                if (form1.p6_ploscek1.Bottom < form1.panel6_pongIgra.Bottom)
                    form1.p6_ploscek1.Top += 15;
            }
            if (godown2)
            {
                if (form1.p6_ploscek2.Bottom < form1.panel6_pongIgra.Bottom)
                    form1.p6_ploscek2.Top += 15;
            }
        }

Nekaj sem poizkušal z keypress in keyboard.iskeydown vendar brez uspeha.