Retros are not connected to Habbo in any way, shape or form. In fact, as you may or may not be aware, they seriously breach copyright law. Many Habbos sign up to these retros using the same Habbo name and password - which means that the person who owns the retro can steal their real Habbo account.
Habbo (formerly Habbo Hotel) is an online virtual world and chat room. It is owned and operated by Sulake. Habbo's main audience are teenagers and young adults. Founded in 2000, Habbo has expanded to nine online communities (or "hotels"), with users from more than 150 countries.