Ceiling paint is paint that is not designed to take any abuse or any cleaning. Hence, it is fairly cheap paint. You can paint your ceiling with wall paint. The sheen depends on how good your drywall work is, flat paints tend to be more forgiving of imperfections in your ceiling. For color, you can do the same as the walls, or go one or two shades lighter on the same paint chip. You can do it a complimentary color, look at the paint brochures at the paint store or paint section at the home center for combination ideas.
Imperfections on ceilings will tend to stand out more than ones on the walls. Ceiling lights cast shadows that highlight imperfections. Walls tend to be broken up by furniture, doors, windows and wall hangings. If the drywall is hung properly (horizontally, not vertically) you don't tend to have vertical seams running from the ceiling to the floor. On a ceiling, you will always have long joints on the tapered edges of the drywall. The butt joints should all be staggered. On walls, these long joints are usually interrupted by a door or a window at some point.