Such a fun square. Some ideas I have seen are to make the oval part a solid color and it can look like an Easter Egg.
The only thing I recommend is that when you are doing Round 4 you pay attention after you have done the 3rd corner-you have to put the first single crochet in the stitch that is now under the corner. Push the corner stitches aside and make your first single crochet. Otherwise you will come up one stitch short.
Also, the last round, instead of single crochet, I did it all in half double crochet, basically to make the square slightly larger.
Also, the last round, instead of single crochet, I did it all in half double crochet, basically to make the square slightly larger.