This game is among Infocom's finest. A sophisticated parser where you can order several robots around makes some original puzzles possible. It is hardcore sci-fi with only little human interaction, so that may not be everyone's cup of tea. But if you are into tough but logical puzzles, this is really good. According to sources, this game has the difficulty level "expert". I didn't find it so hard, unlike many other Infocom games, but that is probably because I like the genre. The game has very high replayability. It has two difficulty levels and for each level you will probably start out receiving a low rank, but by replaying, you can receive the best rank, i.e. rank 1. To reach the highest rank, you will to some extent have to optimize your moves, to have few casualties and to solve the game in few cycles. I regard this as a very good game.
Parser/Vocabulary (Rating: 9/10)
A very sophisticated parser where you can give orders to multiple "characters" (robots). Lacks modern synonyms like X, Z and g and you cannot "undo". A good thing is, that you do not need to type more than six characters of each word, which is a very suitable limit.
Atmosphere (Rating: 9/10)
Though you mainly interact with robots, they have different personalities, not least Poet, and when humans arrive their presence it adds a layer of time pressure.
Cruelty (Rating: Tough)
It quite quickly becomes obvious, that you are not going to solve the game the first time you try. And the first many games you play, it won't really make sense to save your progress, as you will learn something new almost every time, and to complete the game you will probably have to start over and optimize your moves some. But the time limits are obvious. Had there been no time limits it is possible but not very likely, that the game could become unwinnable.
Puzzles (Rating: 10/10)
Excellent puzzles that requires multiple play throughs to figure out in order to provide a challenge. I also like the meta-puzzle of minimizing casualties and the number of cycles taken to finish the game.
Overall (Rating: 10/10)
One of Infocom's best. Some tough but logical puzzles with well-hidden hints. Some might find the lack of human interaction a bit sterile but each robot has its own personality so it didn't bother me. And humans will appear at some point. Very good!