The shapes are looking right, but be bolder! Don't be afraid of using really dark shades and black in the shading. Also the proportions are looking nice.
I really like the horse on the right, looking out of the stall. Very friendly, nicely stylized.
Keep on drawing, you're up to a great start!
Thanks guys! :) The picture was inspired by an add I saw in a magazine. I remember seeing it the other day and thought it was cute! I tried my hardest to draw it by memory.
Thanks everyone for the wonderful tips and I am learning a lot. :) I am eager to start on my next drawing!