Silver and Gold is more of a story and less of an experiment than Origins, though: there’s more at stake, and we get more of a sense of the two main characters and of the way the agency of one constrains the other. There are times when one character or the other is locked in a sort of reverie that doesn’t affect the other; there are also times when one character gets a chance to make a definitive move that alters the other’s state. At a couple of points, seeing the same effect from two viewpoints allows you to grasp what is happening more completely than would otherwise be possible (one character can hear something that is out of earshot for the other, for instance).
The two characters in question are locked in a dark horror/fantasy situation that can end in one of at least two ways (I played several times and found two endings and no obvious directions that might have led to more, but that doesn’t guarantee I didn’t miss something). The content of the story affected me less than the way the story was told — some of the backstory adheres to standard tropes, while other parts are a bit underexplained. Nonetheless, a piece with some cool formal aspects, and the most successful I’ve yet seen to make use of simultaneous dual-viewpoint narration.
Isis is a science fiction piece casting the player in the role of the AI life support system on a sentient space craft. It allows you to respond to your pilot in various ways, including trolling him with disobedient or subversive interpretations of his orders. If you don’t, and behave like a good little spacecraft, then the story nodes eventually start to loop and becomes boring: this creates a kind of meta-game motivation to perform the AI-spaceship-goes-mad trope. It’s not long, but I found it amusing.