The Tetraverse is a universe where all things are completely and forever 4 sided objects. No other shapes exist in this Verse besides Tetrahedrons and Squares/Quadrilaterals everything here, including microscopic to sub-atomic levels, are all squares. Circles here are made of squares as well. Physics and other Math stuff are all the same, as in, just like in our Universe. The only thing is, its much harder, as there are no curves here. Warning: Once you enter the Tetraverse, you will be immediately transformed into a square creature which still has the features here. In this universe, the fastest way to get to another point is by going up, and over.
In this universe, it impossible to play Tetris because some of the pieces are not four sided. It looks like a box