The Horror of Party Beach/YMMV

Angst? What Angst?: Less than a month after his girlfriend gets killed by a monster, Hank returns to the very beach she died on and comments to a band member "pretty dead tonight, huh, Ron?"
- Ron even notes how things have gotten dull since Tina was killed. And not in a mournful way, either.
Awesome Music: The Del Aires were a moderately successful New Jersey-based band.
Designated Hero: Hank. He's a guy who hates fun, for some reason about being too old. (I'll say.) The fight on the beach is caused by his girlfriend's flirting...you know, the girlfriend he pretty much broke up with not just five minute ago. He actually starts the fight, and comes close to actually killing the lead biker by strangling him. The people helping in the fight had to pull him off, and then he tries to break free, like he was a deranged criminal.
Fetish Retardant: The "young people" on the beach dancing... and dancing... dancing...
Harsher in Hindsight: Wonder why the Del-Aires didn't make it big?

On the night of August 25, 1963, the Del-Aires were just wrapping up a very raucous set at the Angel Lounge in Lodi, New Jersey, when two police officers arrived at the club to investigate a noise complaint. Unfortunately, two career criminals – Thomas Trantino and Frank Falco – happened to be at the club celebrating a successful heist they’d pulled earlier that day. Sgt. Peter Voto entered the bar first while his partner waited in the patrol car; he was immediately ambushed by the pair and ordered to remove his clothes. A few minutes later, Voto’s partner Gary Tedesco – an unarmed probationary officer – came inside to see why Voto hadn’t returned; he was likewise taken hostage and ordered to strip. Trantino and Falco then shot the helpless kneeling police officers in the head, killing them both. Falco was shot by police a few days later while resisting arrest and Trantino gave himself up. The Del-Aires disbanded shortly afterward due to “creative differences.”

Padding: The movie drags a bit following the revelation that elemental sodium can kill the creatures.
Special Effects Failure: The eponymous Horrors look like some strange combination of fish, frog, and hapless actor in a bad suit. The mysterious tubes resembling pickles that jut out of their mouths are more baffling than intimidating, and even with these drawbacks, the film still manages to screw up the costume on a few occasions.
What an Idiot!: When the scientist finally guesses where the monsters' lair is:

Dr. Gavin: Fingal's Quarry? Good God, why didn't I think of that before! It's the deepest body of water around here, and it's right near where those three girls were killed.