"The film real science fiction fans have been waiting for!"  That's what we call a lie.

The Deadly Spawn was a fairly dire attempt to cash-in on the success of Alien if the voice-over and the alternate titles are to be believed.  You certainly wouldn't ascertain that fact from the footage.

There are a couple of nice set pieces in the trailer - the 'inside the monster's head' camera angle, and the silly dismembered arm joke.  But despite all the rubber monsters and blood, the most shocking aspect of this movie appears to be the acting.

Favourite bit:  The old lady being bitten on the ankle by a killer space tadpole.