Well we can have info on worlds etc in this topic so long as things are spoiler tagged I think, so in the name of that
beware! here be spoiling spoilers of spoilerage! go no further letst unless you want spoiler information about worlds!
All the current worlds in the game are:
Vaelly, castle, beach, forest, underground, hights, circus, factory, interlectual, volcano, darkness, desert and ice.
Many have two different worlds unlocked, eg, the castle unlocks both the forest and beach.
I'm not absolutely sure which unlocks what, but usually most worlds have alternative paths, and of course there may be new worlds next version the way we recently saw the desert and ice worlds, (I'd love to see a space themed world for example).
Also, once you start unlocking boards, the different boards come with minigames as well. The current boards are default wild woods (which doesn't come with any minigames from what I know), deep water, mysterious cave, and mischievious castle (which is also a great board for earning gems.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)