Click on the background or use the arrow keys to move. Click on your character to change it. Click on the egg to hatch it. Put the mouse pointer over another character to see its username (The characters and the usernames are random). The music is also random; you won't hear the same song twice.
Credit to Animal Jam, the Jambassadors, and Animal Jam Archives. You can report a bug in the comments. This game is also mobile friendly.