Habbo Islands is a cancelled Nokia N-Gage title, which was originally developed by Sulake Incorporation for the Mobile Phone market to debut with their other mobile phone game "Habbo Dreams" which was launched for Sony Ericsson phones in 2004.
The game was postponed due to the development team feeling as though the hardware requirements just weren't there yet, and they put it on the back burner until (around) February 2005 when they started working on a prototype on the N-Gage platform. Said prototype was kept rather quiet, and was shown to a few people behind closed doors at E3 in either 2006, or 2007. The game is estimated to be between 90% - 100% completed, however more than one build of the game has surfaced, the latest being 1.0.7, which was used in order to create the E3 demo.
https://www.youtube.com/watch?v=rtzRaaZXl9s (E3 Demo/Advertisement)
Originally, as many as 50 - 150 copies were made for testing purposes, and it is rumoured that Sampo Karjalainen, and Pasi Ilola are (or at least were) in possession of two of said copies.
UPDATE: A copy of Habbo Islands running on the E3 build of the game surfaced on January, 1st, 2014. It was purchased on eBay with a Nokia N-Gage development unit by the Youtube user "Reiju", and the footage can be found here: https://www.youtube.com/watch?v=Ghz0JZCfpTU