CONTAINS GLUB GLUB SPOILERS
In terms of visual effects, we've been spoilt in recent years. The technology has moved so fast that you don't need to operate on a Jurassic Park budget to come up with impressive computer imagery or physical monster effects, and some quite startling creations can be put together on very little money. Plus, of course, we'll forgive some wobbly FX work if we're engaged with the story and characters, or even if we're not but it's the kind of goofy entertainment that's not supposed to be great anyway (see the likes of Sharknado). Still, genuinely shonky CG can take you out of a movie as easily as one cellist scraping hard at the wrong notes can take you out of the whole symphony: a pity when there's as much good stuff on offer as bad.
The Microsoft Paint-level effects aren't the only problem with The Creature Below, but they're the most noticeable because they show up first. Olive is a deep-sea research diver working with a new suit that will allow her to go further down than ever before, but on the first test dive she encounters something in the depths and blacks out. Fired by her unreasonably hateful boss (who is obviously doomed a couple of reels later), she returns to her suburban semi with an egg-like thing she discovered lodged in the ruined diving suit: under her care it begins to transform into a larger creature with a hunger for human flesh and blood....
There's a fair amount of Lovecraft and Cthulhu, the ancient god of unpromising Scrabble racks, on offer (Olive has a certificate on her basement wall from Miskatonic University); the physical effects are pretty impressive, particularly on the smaller creature, there's comfortably enough blood and gore for the 15 certificate, and the apocalyptic ending, the very definition of "well, that escalated quickly", is terrific. The three-way domestic tension between Olive, her boyfriend and her sister is entirely uninteresting, but it does give the opportunity to chuck some more bodies into the basement (the moment where Olive discovers her strange and interesting new pet's attraction to human blood is very similar to Rick Moranis and Audrey II in Little Shop Of Horrors). Agreeable fun, but the CG lets the side down.