Have you tried art? Cut sponges into the shapes you wish to teach, dip them in tempera and stamp them on paper. Kids can carry a card with a shape on it and then find it in the room. It could be a block with the same shape, the window, top of a jar, etc. Sort of like a shape scavenger hunt.
Cut shapes from heavy cardboard or use the special math attribute blocks you can purchase, have the kids feel the shapes, good if you have them in different sizes. Eat shapes, find crackers in different shapes, sort and eat, make large shapes on the floor with tape, walk around the shapes, sing the name of the shape as you go, jump in the square, sit in the circle, make up games with the shapes on the floor.