Comment by Bluestein

The author explains:

"Each letter and digit in this typeface is made up of exactly one of each of the Tetris pieces: (I), (J), (L), (O), (S), (T), and (Z). Furthermore, the letter is designed so that it can actually be constructed by stacking these pieces one at a time and be supported by previous pieces, as in Tetris. These designs were found by hand, aided by the BurrTools software which enabled searching for whether the Tetris pieces could fit inside a candidate outline for a letter. The piece colors roughly follow The Tetris Company's standard colors, or you can switch to black pieces. The initial rotations follow the standard Super Rotation System."