High Water Mark for Interactive Fiction
What are text adventures best at, that graphic adventures cannot do? They relate everything via text, so if you are simuating a sense like smell or thought patterns based in Shakespere, you can only do it here. That is the point of this game, where you try to save the world by assuming the personas of 5 different robots, who each percive the world in diffrent ways. Thus, only by getting them all in the same room can you truly understand what is there. Also, game is slightly "replayable" (you get a score based on how efficently you solved the puzzles).
Hard due to the subject matter, but oh so rewarding when you figure it out.
The Bottom Line
The best (and most abstact) adventure game of our time.