If you can forget about September 11 or at least put off your thoughts about it for the few hours it will take to play this game, you will discover that Vicious Cycles is an excellent gem with some unfair puzzles that are overshadowed by the excellent plot that you will reflect upon long after the game is over. I don't want to spoil the plot in this one, so let's just say that similar to Tapestry, Vicious Cycles will force you to make a difficult choice between saving your friends and saving the world, and each choice has its own ramifications you need to think about.
The plot unfolds in a similar way to Andrew Plotkin's Spider and Web: you start out the game not really knowing who you are, or what will happen next. Then you will die, and forced to go through the "vicious cycle" again, each time gaining more knowledge about what you need to do. Similar to Rematch, dying is a necessary action in order to get to the "optimal ending" of the game, except that similar to Tapestry there really is no "best" ending: just a few different ones that show the consequences of the choices you make. Puzzles in the game are logical, although some are a bit weak due to insufficient clues, and some feel out of place. Still, by the end of the game I was thoroughly absorbed in the plot that I was willing to forgive the game for its puzzles (which aren't so aggravating anyway, just annoying). The writing unfortunately doesn't bring out as much emotional impact as it possibly could, but it is still more than adequate. If you like "go back in time to change the course of history" games a la Trinity, Vicious Cycles is well worth your time. Highly recommended.