Clock Tower is a point and click style survival horror. Basically, you are in a house being pursued by a serial killer. You can't really fight, all you can do is solve puzzles and hide whenever you hear him near. It has lots of different endings, so there is a bit of replay in terms of how you play - save everyone? Just yourself? Stop the killer? or just get the hell out of town?
If you're not a fan of point and click games, or survival games as a whole, stay away. It is very similar to its two sequels on PS1. Not all that similar to CT 3 on PS2.