Good old school adventure with interesting story behind.
Be warned however - could be hard to enjoy this game running it on XP or Vista due to stuttering and mouse problems. Also in the year of 2008 (as I am writing at the moment) the graphics and sound are hardly enjoyable - they don't hurt that much, they don't help either. I give Sanitarium a score of 8 since I was expecting all these flaws from a 10-years-old game but still enjoyed the gameplay a lot.
The puzzles are not too difficult and don't get boring, most of the story envelops logically (well, for a game about insanity...) and you don't have to click frantically on everything in order to push the story forward. Most dialogues give you hints as what to do - just be quiet and listen :)