Try:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.Up)
{
Top -= 20;
return true;
}
if (keyData == Keys.Down)
{
Top += 20;
return true;
}
if (keyData == Keys.Left)
{
Left -= 20;
}
if (keyData == Keys.Right)
{
Left += 20;
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}