Starcross has imagery that sticks in the mind, even after two decades: colored rods. Why these rods would be so -- hmm, I want to say "primary," and I don't just mean in coloration -- distinctive and mind-etching, I'm not sure, but if you're talking to someone about playing an old Infocom game, and they say, "Which one is Starcross, again?" and you say, "The one with the rods," they know exactly what you mean.
You find yourself on a large cylindrical spaceship of alien origin, with all systems controled by fitting these rods into like-colored slots. You start the game with none, but you need all of them to get to the end. Thus, the main thrust of the game is finding these rods in their various hidden places, and solving the puzzles that keep them from easy acquisition. It's not a bad way to plot out a puzzle game; in fact, it's archetypal at this point, although you can't really do colored rods any more without its being a complete ripoff. Instead, to this day one can still play new IF games that involve finding different colored widgets and fitting them into wodgets.
The various ways of dying in the game reveal a meta-plot at work: (Spoiler - click to show)the reason everything is so puzzly and challenging is, apparently, because the race of aliens that created the spaceship are trying to find lifeforms intelligent enough to bother with. You are a lab rat in a little maze of death traps, basically, but you can eventually prove that you are a sentient lab rat.
Some of the puzzles are clued pretty well, and some of them are rather notoriously unfairly clued. The red rod, in particular -- (Spoiler - click to show)one of the first you need to get, because there is a time-critical aspect to doing so -- shapes up as a guess-the-verb situation, with not enough feedback along the way to point you to the correct solution. I think the main failure is that the author pictured the obstacle quite differently in his mind than he ended up describing it.
Apart from the trouble with the red rod, I managed to push through this game, which 21 years ago I found impossibly challenging, on my own. Indeed, I experienced one of those primal moments of IF pleasure while playing this game. I was frustrated with not being able to find any more rods at one point, and traced and retraced my steps, and couldn't see what would produce progress. I decided to quit the game. Just as I did so, a new thought popped into my head: "Hey, what if I ...?" I reloaded the game, tried my idea -- and it worked! It's been too long since I allowed myself this kind of pleasure; it's too easy to go to the Hints or a Walkthrough or ask a friend for help these days. But the only way to get this feeling is to solve a toughie unaided.
The game has quite a few NPCs, all of them about as shallowly implemented as you would expect for a 1982 game that had to work within severe space and memory requirements. A little bit of lively writing goes a long way in these cases.
Overall, quite good, but showing signs of age. For puzzle-solvers, I don't think it'll ever go completely out of fashion, and the concept of colored rods and slots will live on in the collective IF consciousness for years to come.