From a pretty average start `Grabbers' soon gets going and shows its true colours, i.e. it's not just a horror, but a pretty tongue-in-cheek comedy. And that's where its strength lies. It's at its best when it's being slightly cheeky. Yes, there's a reasonable amount of gore (but not that much). What little budget there is has been spent on the creatures themselves. And, for a mere (in Hollywood terms) £2 million the monsters are actually pretty well done. They're all computer-generated, but the CGI fits in seamlessly with the real actors all around them.
The film is about a sea-full of tentacled monsters who descend on an island off the coast of Ireland and start sucking the blood of the hapless locals. However, as luck would have it, these beastly parasites are allergic to the taste of alcohol. Therefore, all that needs doing to survive is getting out-of-your-face drunk. Of course, fighting back while plastered is actually quite hard!
Also, the film benefits from seeing the monsters (in the full) early on. In other similar monster-movies, you only get to see a tentacle here or there until the final scenes (normally to save on special effects), but here you see them `full frontal' from pretty early on.
Most of the characters are hardly developed, but if they're funny then we can forgive that.
If you're a fan of such cinema greats (!) as `Deep Rising' then this is in the same cheeky little league of its own.