There have been so many low-budget shark-attack movies at this point that their creators have to do something really different to stand out from the pack. Thus you get something like Sharktopus, an insanely stupid idea that nevertheless captures the pop-culture zeitgeist for two minutes precisely because of its insane stupidity. Sharktopus comes from two proud traditions of B-movie schlock: It's produced by low-budget legend Roger Corman, and it was created for Syfy, which despite its fancy name change is still in the business of churning out awesomely awful horror/sci-fi TV-movies on a regular basis. What makes Sharktopus stand out from dozens of other terrible Syfy productions? Other than its title, pretty much nothing. It's sloppily constructed, with terrible acting, atrocious special effects and a thin plot that strains to fill 90 minutes. Like a lot of micro-sensations that generate interest online, its entire appeal is in its title and maybe the trailer; watching the movie is essentially redundant.
But I watched it anyway, and it wasn't a horrible experience. Corman has decades of accumulated knowledge in how to package this stuff so it goes down easy, and even abiding by basic-cable standards, he knows how to throw in plenty of scantily clad hot women (the movie takes place mostly at a resort in Puerto Vallarta) and evenly space out the gory moments, plus add the requisite comic relief. All of that stuff is there, just in kind of a watered-down form. Obviously the women have to remain clothed, the violence is pretty tame (although there is plenty of blood), and the comic relief is mild. I did enjoy Ralph Garman as a snarky radio DJ who scoffs at the existence of Sharktopus (naturally right before getting devoured by the half-shark/half-octopus creature), and there's some camp value in the obviously clueless way the actors react to being attacked by a post-production special effect they can't see.
That's pretty minimal entertainment for a 90-minute movie, though, and it's spread thin enough that the rest of the time is filled with boredom, including repetitive exposition and scenes of irrelevant characters who are never seen again. Eric Roberts is the only semi-respectable actor in the movie, and most of the time he looks like he's just biding his time until he can head back to his trailer. Even the way he wears his sunglasses halfway down his face looks condescending. He plays the head of the scientific organization that has gone too far in creating the Sharktopus as a weapon for the military (why does the military want a Sharktopus?), but he spends almost the entire movie on some yacht in an undisclosed location, like he was annoyed at the prospect of sharing too many scenes with the other actors. That kind of half-assed boredom with the material pervades the movie; so many people online were taken with the supposed awesomeness of the concept, but the people making the movie don't seem nearly as impressed.