By far the more popular and more widely-available Twilight parody novel on the market, Nightlight was a huge disappointment. For a book written by the Harvard Lampoon - you know, IVY LEAGUE HUMOR PEOPLE - it's painfully dumb. Painfully. Perhaps it was my mistake for expecting something, I dunnno, more from them, but I went in to Nightlight hoping for some kind of relevant, witty commentary on Twilight's failures as a book. You know, jokes about the faults of its characters, the absurdities of the storyline, or lack there of. I expected something smart. In reality, the level of humor here can be accurately surmised by the monikers the Lampoon has bestowed on its lead characters. If you think Belle Goose and Edwart Mullen are downright HILARIOUS variations of Edward and Bella's names, then you may possibly find Nightlight funny. If, however, your reaction was closer to "Really? Is that the best you could come up with? Was that like...funny to you guys?" then you'd probably be better off avoiding it.
It's a shame, too, because there were some amusing concepts and ideas presented in Nightlight that suffered terribly from skewed development. The idea is that Belle is delusional - she convinces herself that Edwart, your everyday unremarkable nerd, is a vampire because she wants him to be. Vampire boyfriends are cool, man, so she actively shoehorns him into that mold. Belle sees supernatural attributes where there clearly are none, and at points goes so far as to instruct Edwart in how to behave more like a vampire would. For example, she orders him to be more possessive and controlling of her - despite Edwart's obvious discomfort with it - because that's how vampires treat their girlfriends in the movies, hurhur. It's more a parody of the fangirl mentality than of Twilight itself, which could have worked fine, if more effort and intelligence had been put into it. Instead, aside from one or two amusing bits in the beginning re: Bella's mom, the Lampoon settles for nerd jokes and pratfalls rather than any meaningful satire.
It's mind-boggling as to why, with a series as rife for parody as Twilight, the writers chose to take the delusional fangirl schtick and run it into the ground. If it weren't for the way the book mocks Stephenie Meyer's writing style, I'd wonder if the writers had even read Twilight at all, or if they'd simply settled for gathering their material from what they'd seen on tv and heard from their girlfriends and younger sisters. We get no kind of love triangle parody at all, which is absolutely absurd to me considering how much of Twilight, as a series, is devoted to that triangle, but how could we when there's not even a Jacob-equivalent character, if you can believe that. We really get no commentary on Bella's characterization except for her clumsiness, which is played often and loudly like she's a lost member of the Three Stooges, nor do we get any real parody of the increasingly ridiculous plot points throughout the Twilight series.
Instead, at the last minute we get a random twist that involves Belle dating an actual vampire for a chapter or two, where she discovers the moral of the story: that dating an immortal asshole probably isn't all it's cracked up to be. Again, it's a nice idea, but aside from presenting said thesis in the most obvious way possible, that twist completely fizzles out and goes nowhere. Hell, even the Vampire Prom at the end - literally, a separate prom for vampires, probably the only joke that does garner a chuckle simply by existing - is wasted because they do nothing with it. It's just there. And for some reason, the authors have decided that things just being there is enough of a reason to laugh. And it's really not.
Nightlight's saving grace is its brevity. At 150 pages, it's something you can breeze through in an hour, if you really feel like sticking with it that long. Personally, I'd say don't even bother with it at all.