Run the project and you should either be able to move the girl or the boy or be told you're only viewing. If a second person runs the project while you're running it they should gain control of the other character. You should see their character move and vice versa. Use arrow keys to move, space to change costume. This uses one cloud variable for each character. A second cloud variable is used to record the username for each player but this can be ignored if not required.
THANK YOU DECK26