Bad script, bad acting, bad everything. If you find black goo spooky, then this is for you. Of course, there is more than black goo. There's the young kid who happens to know about the "evil" in the house, without experiencing anything. How does he know this? There's the doctor who sends dad home with no stitches for wounds he would bleed to death from. (Of course, this is done all the time in real life.) There is the cliche old lady who happens to have keen insight into the source of the evil - but then is killed (in a really stupid way) too soon to have any significance. Then there are the unexplained swastikas. In fact, there is so much wrong with this movie, it would take less effort to re-write the script than to explain it all.
This movie is pure cheese. Of course, it has the Amityville name on it, so I see it every other year or so to remind myself how bad it is. Why is it that the people who make these movies cannot see that what they produce is NOWHERE near the caliber of the original?