Rating: 10/10. Creepy and immersive.
Author: Michael S. Gentry
Download Anchorhead for free
Spoiler filled maps of Anchorhead
(You might also be interested in Emily Short's review, "Aweighing an Anchorhead".)
It starts out simple. You've moved with your husband to the small town of Anchorhead. Your husband inherited an old family mansion and managed to get a position teaching at the local college. All you need to do is to do is visit the real estate agent to get the keys to the house. But something is wrong. Very wrong.
This is interactive fiction as interactive fiction should be. You have clear motivations: early on move into your home. Later, save your family. Everything logically flows from these motivations. The puzzles don't feel like puzzles; instead you're facing real problems to solve. Many are puzzles are difficult, but all make sense in context.
This is horror as horror should be. The horror slowly builds up. Things start relatively simple, but by the end of the game things are spiraling out of control. The actual horrors are internally consistent, if alien. You don't face a random series of horrors, everything ties together in a single horrific plot.
Anchorhead is, at this point, the best piece of interactive fiction I have ever played. After playing Anchorhead it was hard to feel able to start a new game; everything else felt like a let down. While perhaps a little difficult and long for someone new to interactive fiction, I highly recommend Anchorhead to anyone with a few interactive fiction games under their belt.
(2009-01-05 update: Minor corrections.)