In this one-room, complicated game that upends IF conventions, you must extinguish all of your many lightsources to let a grue eat the troll blocking your way.
Adventurers may recognize the lantern from Adventure and Infocom games, the elvish sword from the Zork games, and the amulet from Spellbreaker. There are several other lightsources to deal with. Other items from Infocom games include the stock certificate from Zork III (I think), the grue repellent from Zork II, Zork III, and Sorcerer; the screwdriver from Zork I; and many others.
This game is hard. Like many others, I played for over a half hour without extinguishing a single light source. But once you start to get a feel for the game, it gets better and better. Because of an early experiment, I got the wrong idea about one item and never solved one of the harder puzzles on my own.
I recommed trying to get half of the points before using a walkthrough.