I don't want to come across as beating a dead monster baby and give this film more time and space than it really warrants but I forgot to mention something about IT'S ALIVE that is important.
That's the musical score by maestro Bernard Herrmann. Sonically, the music prefigures what he wrote for Martin Scorsese's TAXI DRIVER (1976), which was Herrmann's last movie score. The music for IT'S ALIVE is not as good as the classic material he wrote for THE DAY THE EARTH STOOD STILL, JOURNEY TO THE CENTER OF THE EARTH, several Alfred Hitchcock films (VERTIGO, NORTH BY NORTHWEST, PSYCHO) and the wonderful fantasy films of Ray Harryhausen (7th VOYAGE OF SINBAD, JASON AND THE ARGONAUTS) but still, any Herrmann score is better than no Herrmann score. I just felt I should mention that important contribution to a minor film.