I recently picked this up on VHS under the title "Ghosthouse 2", although it has nothing at all to do with the original Ghosthouse film. I was expecting it to be terrible, after reading IMDb reviews, but it actually turned out to be OK. The setting of the film is what gets the most marks from me - I love seeing the shots of the house and island from the sea. It's THE perfect setting for a horror film. I do think it was a little wasted on this particular film though. Never mind.
The film itself isn't too bad, it just drags a bit in some places and I didn't like the witchcraft theme. I found the scenes where people are transported via that "Doctor Who" style vortex extremely cringe-making. It looked like something from a cheap 80's sci-fi film! Other than that I thought the death of the old woman was excellent - she gets her lips sewn together and is hung upside down above a lit fireplace. She can't scream for help and the others have no idea she's there. Now there's an original death for you! The parts where the helicopter flies around the house are also excellent - the people inside can't signal for help because the house has trapped them inside.
I would recommend horror fans to give this a watch, it's silly and boring at times but the good bits make up for that.