(It isn't just one of those things that lure you to turn up your speakers and then screams at you ... although it does have a somewhat loud ending in the Corridor, so you should be safe if your sound isn't too loud to begin with. I just wanted to include that disclaimer and warning, since I hate having those stupid practical jokes blow out my eardrums).
The Dining Room is sort of an interactive flash puzzle horror story. Not very complicated (try clicking on things multiple times), but creepy and atmospheric, with nice sound effects. Turn off all the lights in your room before you start to make it really scary!