I think this sort of criticism almost sounds unfair, but this game just has too much content. Optional content, mind you. Stuff normal people (not me) would just ignore. Basically, to truly complete this game, you have to play the whole thing over again without the ability to mark empty spaces with crosses. Considering how many boring subway commutes this game helped me through, I guess I can hardly complain, but I think a few side modes à la the Picross series would have been a much better fit. As it is, the sheer monotony of it all had me relish in the thought of finally being done more than that of just playing the game by the end.