Yes.
You can change your username and password by going to "My Account" in the support category.

When you register a user ID, we send an e-mail containing your user ID and password information. Please save the e-mail.

In the event you lose your password, please reissue your password by going to
"Forgot Password".

You can change your player name by purchasing "Change Player Name" in the Miscellaneous section of the in-game shop.

The sharing or assigning of accounts is prohibited in the users agreement.
The use of another person's account and password is also prohibited.
If either of the above events should occur, service to the user may be terminated without prior warning.

If you were not able to receive your confirmation email because it was blocked by your email provider, kindly re-register using a different email address.
Please make sure to adjust your whitelist settings to accept anything coming from SplashFighters by allowing *@splashfighters.com.
If this still does not work, please try creating a new email address using Gmail and re-register using that new email address.
Always make sure that you have typed your email address correctly before clicking on the "Submit" button.