Roger Corman once mentioned in an interview something to the effect that when he looked in on the filming of a comedy, he knew everything was all right if the cast and crew were joking and laughing and having a good time. In his experience, that energy would translate to the screen and the picture would be funny and enjoyable.
Although Corman did not produce this particular picture, "Beware! The Blob" looks to me to be exemplary of this kind of thinking. The cast was obviously enjoying the experience of making the film, and we, the audience, get the benefit. A certain sense of giddy frivolity is evident.
This movie was made by Jack Harris and Larry Hagman in the 70's--the early 70's. And by golly, it shows. Many people hate this film, and part of me wants to shout, "C'mon, guys, this is great stuff! You're watching it the wrong way!" But really, this film isn't for everyone. Not everyone likes grape jelly. Or strawberry jam. And that's...okay.
I would say this sequel to the (excellent) "The Blob" is played half-seriously, and that's why I find it so strange and refreshing. Sometimes it's a raucous farce. Sometimes it's straight horror. And oddly enough for a 70's film, it seems to know when it is being one or the other, and keeps true to whatever it is at that moment. It's not nearly as badly made as many of its detractors claim.
Watch it for the pea soup-thick 70's atmosphere. You'll feel as if you've entered another world. Watch it for the inventive low-budget special effects. A few shots look pretty nice even today. Watch it for the scene with the bald would-be victim guy in the bathtub, who throws the phone through the window when he sees the gelatinous menace oozing under his bathroom door, and who is then seen running starkers through the streets, shouting, while funny music plays. "Beware! The Blob" is extremely goofy, exciting, brightly-colored fun stuff. It is extremely representative of the era in which it was made.
Trust me: There is NO movie that entertains the way this one does. See it and treat yourself to a fun bit of film!