Stack-up gets hate for being a R.O.B. game that's "just stacking blocks". Yes, for the most part, rearranging blocks is what you mainly do that while in single-player mode. However, the two player versus mode "Bingo 2 player" is where this game shines, and most reviews don't talk about it. The multiplayer mode is definitely the best part of the game. You and a second player basically battle over the control of R.O.B. and try and get him to move blocks over to your side of him before the time runs out. You move around a grid pressing buttons that correspond with commands for the movements of R.O.B. You and even run into the other player to knock them off course. The gameplay can be a bit slow with R.O.B., but it is still be fun in multiplayer.