There are currently SIX worlds in your Tripeaks adventure: Tiki Beaches, Tiki Skies, Tiki Seas, Tiki Paradise, Tiki Prehistoric and Expert Levels. Later levels will unlock as you complete earlier levels.
To move between worlds:
1) Click the 'Islands" icon in the upper-right of any Island screen
2) Slide to the Island you wish to play and click to enter
You can only enter Islands you've unlocked.
Tiki Beaches last level is 216, Tiki Skies last level is 162, Tiki Seas last level is 700, Tiki Paradises last level is 1050, Tiki Prehistoric is still in the makings!