The poster and the television ad featuring the ghoulie in the toilet was reportedly this to small children back in the day, and filmmakers got many angry letters from parents because of it.
While the puppetry and slime-effects are terribly cheesy by post-80s horror standards, the scenes of the party-goers' corpses writhing their way across the floor still hold up very well. For all that the performers' vocal acting leaves a lot to be desired, their miming is quite impressive.
Jonathan trying to entrance Rebecca during sex is the equivalent of him drugging her so as to have his way with her. In other words, it's rape. It looked pretty creepy even then and looks even worse now.
