You can play the game using your old e-mail account and password. It is not necessary to change the password in order to use the application on a new computer. However, there is no information on how to recover or change the password. If you have lost the password, try checking the mail that you used to register. You might still have the password there. The contact page from the official website is unavailable, so there is no way to contact the developer regarding this problem.
