Story - This manga is a collection of short horror stories and range from curses caused by tainted water to parasitic type stories. All of the stories were exceedingly gory and some were quite disturbing but predictable. I got confused quite often as the stories would often jump backwards and forwards between stories that been told in earlier chapters and it was difficult to recall the characters and what had happened to them.
Art - I believe this manga was drawn in the late 80s so the art isn't amazing but I felt it fit very well with the creepy nature of the manga and the gore was drawn very well indeed. Some of the drawings were very disturbing and for an early manga, I felt it did this very well.
Character - There are not very memorable characters in Horror Mansion, mostly for the fact that it is a collection of short stories and you will generally only see character for a chapter and more often than not they will come to some grizzly demise.
Enjoyment - I read this manga while waiting for a train and actually quite enjoyed it and didn't put it down until I'd finished it so I think I enjoyed it quite a lot.
Overall - Overall, I enjoyed this manga. However, if you do not like horror/violent/gory manga, this manga is definitely not for you. If you do, sit back and enjoy the madness!