The first time I played this game was at 2am with all the lights off and the only sound and light coming from the TV. I was scared out of my wits.
This game is one of the best PS2 games I have ever played. It is so easy to get absorbed into it, and after a while the noises and ghosts start to get to you.
The graphics are absolutely stunning, with a 50hz or 60hz option, although the 60hz option would not work on my tv. The main weapon is a shotgun like light gun that is powered by the ghosts themselves, and a grenade which you can use to trap ghosts.
All in all, if you're looking for a good scare, or an excellent shooting game, give this a buy or at least a rent. It'll be well worth your money.