I'm assuming that you're referring to the Tetris Holding, LLC v. Xio Interactive, Inc. case. My opinion is that only the color choices in Mino and possibly the placement of the next pieces display relative to the game board should've counted as infringement. Everything about the board size, the piece geometries, the piece movements, and the existence of the next pieces display, the number of pieces in the next pieces display, and the existence of 3D-like lighting should have been treated as ideas or functional elements with respect to the idea–expression distinction and the merger doctrine.