Your uncle was fond of practical jokes, it seems, and his last and greatest joke, now that he's dead, is to turn the whole family into chickens when they show up to squabble over his estate. The challenge is to overcome your newfound limitations and find a way out of the problem, using your uncle's various wacky inventions that litter his study. The inventions themselves are at least as amusing as the premise, since they include things like the Hedge Helpers (a pair of hands to extend one's reach) or the Buffalo-on-a-Spring. There's really only one puzzle, but it's quite a puzzle--it involves all sorts of clever mechanical finagling, and the various peculiar devices are described well enough to make the puzzle solvable. (Well, mostly--there are a few slightly misleading responses.)
The point of Foggywood Hijinx is the humor, obviously, and there's enough of it to keep the game going for a while. Notably, a TV features Julia Child raving dementedly about the joys of killing chickens, e.g.: "I once killed a chicken just to watch it die." Your various bickering relatives continue to bicker in chicken form, but in more amusing ways: "Uncle Orpington pulls a long strand of fiber from the carpet. Cousin Red jealously tries to snatch it away, and a tug-of-war ensues." This wouldn't be enough to sustain anything other than a very short game, of course--and it might not be enough, depending on how long it takes you to figure out the puzzle, to get through this one without the jokes getting stale. Still, there are a few chuckles here and there, which is all that can be asked of a chicken-comp game.
In sum, it's funny enough to be worth the 10-15 minutes, and if you haven't already seen too much IF involving chickens, it's worth a shot.