In my opinion, "Return To House On Haunted Hill" was a very good sequel to "House On Haunted Hill" (although it would have been better if one or both or the survivors from the first movie had been in this).
It is gory, suspeceful, and has mostly origional deaths - what more could you want from this type of movie? There were a lot more people in the house this time than in the first (about 10) so there is a higher body count, too.
Althought there is quite a lot of gore in this movie (a lot more than in the first movie) it wasn't as gory or over the top as most people were suggesting. But the best thing about the movie I thought was that, while most horror movies either concentrate on either being suspenceful and creepy, or on being violent and bloody, this movie had both gory deaths and suspenceful scenes, so you get the best of both worlds.
Overall a very good sequel, which I'm sure fans of the first movie will enjoy. After seeing this I'm certainly hoping that there will be a third movie in the series.