This is a volumetric 3D chess where pieces can move XYZ (Vertically and horizontally) the pawns above the standard chess pieces are there to slow down the beginning of the game and prevent immediately ending games... If there was nothing there the special pieces could quickly jump up and the first player to do that would quickly clear out the opponents pieces.

They second row of pieces are also there to add more pieces due to the game area being 4x larger than regular chess so that there isn't too much empty space

This is also a capture the flag variant with a "fog of war" mechanic, meaning that opponents pieces are invisible untill they are in the immediate line of sight of your pieces.

If you have more questions I am happy to help and hope that you try the game again, there is also a tutorial in game explaining how to play