type
  TWall = class(TPhysicalBoxSprite);

  TBottom = class(TWall);
  TLeftWall = class(TWall);
  TRightWall = class(TWall);
  TTop = class(TWall);

implementation

procedure TForm1.FormCreate(Sender: TObject);
 
  [...]

if AdDraw.Initialize then
  begin

    [...]

    with TTop.Create(SpriteEngine) do
      begin
        Image := ImageList.Find('wall');
        X := 0{ + 1};
        Y := 0{ + 1};
        Typ := ptStatic;
        Width := 800;
        InitializeShape;
      end;

    with TBottom.Create(SpriteEngine) do
      begin
        Image := ImageList.Find('wall');
        X := 0{ + 1};
        Y := 600 - Height;
        Typ := ptStatic;
        Width := 800;
        InitializeShape;
      end;


    for i := 0 to 600 div 50 do
      begin
        with TLeftWall.Create(SpriteEngine) do
          begin
            Image := ImageList.Find('wall');
            X := 0{ + 1};
            Y := i * 50;
            Typ := ptStatic;
            InitializeShape;
          end;
      end;

    for i := 0 to 600 div 50 do
      begin
        with TRightWall.Create(SpriteEngine) do
          begin
            Image := ImageList.Find('wall');
            X := 780;
            Y := i * 50;
            Typ := ptStatic;
            InitializeShape;
          end;
      end;

  end;
end;