こんな感じすかね・・・?

procedure TForm1.Timer1Timer(Sender: TObject);
begin
if GetKeyState( VK_LEFT ) < 0 then
begin
imagelist1.GetBitmap(1, image1.Picture.Bitmap);
end;
if GetKeyState( VK_RIGHT ) < 0 then
begin
imagelist1.GetBitmap(3, image1.Picture.Bitmap);
end;
if GetKeyState( VK_UP ) < 0 then
begin
imagelist1.GetBitmap(2, image1.Picture.Bitmap);
end;
if GetKeyState( VK_DOWN ) < 0 then
begin
imagelist1.GetBitmap(0, image1.Picture.Bitmap);
end;
Image1.Refresh;
end;