The Polyverse is the main HUB world in Flat Pack Puzzler. To approach levels, you must go to certain areas, so there is no set order, but levels are unlocked after completing others or certain achievements.
The levels are divided into 10 sections and suburbs. Inside them is 6 levels, with more to be unlocked later and a boss battle. When you defeat the boss on one level, the next one is unlocked.
Although no playable representation for the series, Flat Pack Puzzler is represented by the Mini Cube item, a few summons and the Polyverse stage. It starts on the happy Polygonopolis town hall, where you are on top of a cube being built, it is knocked down and you return to your platform, where you head to the suburbs of the Polyverse into Icy, Desert, Mountanious and Grassy areas, before returning. The same stage appears in Stelios Scramble and Fusion vs. TsuKai.