Is it possible to download it here?
From The Lost Media Wiki
I found this site, is it possible to download it? --> http://sonata.melodimedia.com/content/search/ (search "habbo")
Also, is it still possible to send an SMS and get the game? I only say this because through the wayback machine the game was obtained through an sms code as evidenced: http://web.archive.org/web/20070514071640/http://www.habbomobile.co.uk/games.aspx?c=GB&lang=en&handset=0
And no, dreams have never been lost media, I can find forums and old sites that have the game.