I saw over on MMOGames.com that they had this alpha key giveaway to test a Unity 3D based MMORPG which also comes with a “build your own level” functionality.  I played around with it. Kind of interesting. Sort of Second Life meets FreeRealms with clients in your browser, on your desktop, and on iOS/Android.

Check it out here to get the Alpha code:

http://mmogames.com/giveaways/the-missing-ink-alpha-key-giveaway

Or the direct link here:

http://www.missing-ink.com/