I saw this movie on HBO a couple of years after its release and really related to the characters (being 13 at the time). It's a time capsule. Anyone considering making a movie set in the 70s should view this film to garner some ideas for period detail.
Imagine my surprise when the gang from Kenny and Company, minus Kenny, turned up in "Phantasm"!
Update - 11/2006: Saw it again on DVD after 26 years and it held up well. I was impressed with Fred Myrow's music and I really enjoyed the 360 degree shot of the vet's office waiting room when they took Bob in for the final appointment. The combination of those two elements, the music and the touching content of that scene, provided the "emotional glue" (to borrow a Coscarelli phrase) of the film for me. Nobody needed to cry; the director allowed us to connect the emotional dots. Brilliant.
If I ever make a film, I hope its half as good as this one.