Here's a great adventure game nerd analysis of the types of puzzles you'll find in adventure games. As a lapsed adventure game nerd, I thought writer Mark Newheiser it did a commendable job of breaking down the component parts of the genre.

But he also highlights why it's difficult to write about adventure games.

...the core features of gameplay cannot be effectively evaluated without actually playing it or giving so many details away as to detract from the experience of playing the game. In many respects, the quality of an adventure game depends upon the quality of its puzzles, whether they are ingenious and rewarding or just frustratingly illogical. Having been told an explanation to how a puzzle works means you will never be able to play it as intended, since a big part of the experience is the enjoyment of figuring it out for yourself. You can evaluate the art, voice acting, and even the story or humor present in an adventure game to a certain extent without diving too deep into it, but an adventure game with terrible puzzles can make all those other elements irrelevant, since you likely will never have the patience to finish the game in the first place.

In other words, the genre is uniquely susceptible to spoilers. Newheiser also concisely sums up the appeal of adventure gaming:

Puzzle solving in all of its various forms is probably as old as games themselves. Rather than making strategic choices, testing reflexes in real-time, or engaging in competitive activities, the challenge is to come up with a precise solution.

The site is Adventure Classic Gaming. It also redirects from classicadventuregaming.com, which makes more sense to me, but so long as you get all the adjectives in there, you're golden. They've also currently got the only non-useless review of Vampyre Story, the latest from a former developer of the some of the classic Lucasarts adventures named Bill Tiller. The review had me at this bit:

In contrast to the almost "family friendly" LucasArts games of old, yet fitting to the theme of a cruel vampire hunting for an innocent bride, A Vampyre Story takes on itself to delve into more "extreme" contents. The game contains swearing, tongue-in-cheek sexual innuendos, and gory descriptions about death and torture.