I like the tower a lot. It's a cool design. The basic form is a cylinder (this is a great lesson to brush up on cylinders in perspective: https://www.proko.com/course-lesson/how-to-draw-cylinders-and-ellipses/comments) Overall you did a great job following the perspective, but I think some of the contours that are further away feel a bit flat. As the tower increases in height, the width of the ellipse that represents the contour will increase also. At the horizon line it will be perfectly flat in line with the viewer.