You click on Nano first, then the girl and lastly the cat. And when you press the cat, you will hear the birthday song. And also when you press the cake, it gets a little bigger and then it goes to its normal size. Oh and I almost forgot, when you press the background the balloons and the ground will change colors. I hope you like this :) Don't forget to favorite it and love it.
I just got help from the tutorials because without them I wouldn't have made this first project.