Basket Case is a wonderfully odd film. Despite the terrible, terribile acting, there is a gloriously unsettling atmosphere to the film, and while it is often billed as a horror comedy, the film really qualifies as a great cult horror flick that will unnerve many viewers when watched with the right frame of mind. It tells the story of Duane, who is tracking down and offing the people responsible for him being separated from his conjoined twin, namely the freakishly deformed Belial.
Belial is carried around in a big basket, and for a good portion of the film, you don't see all that much of Belial. This works in the film's favour, as it really gives some impact to the big unveiling. The thing is, the people behind the effects on this movie did something very clever with the creature. The Belial models and puppets look rubbish (you can clearly see the mould seams in the rubber, for example), but the creature has been given some extremely lifelike eyes, which are the source of much of Belial's creepiness.
In fact, Belial becomes something of a sympathetic character towards the end of the movie (especially after the gruesome flashback sequence where he is removed from Duane's side), and while the entire cast doesn't seem to feature a single actor amongst them (aside from maybe the landlord of the apartments where much of the action takes place, as he's just cool), their performances are uniformly bad to the point where it just works really well.
It's a very odd film, with an undeniably creepy atmosphere, and with some clever use of stop motion in some shots, some effective shock moments (shoving someone's face into a drawer of scalpels, only for them to emerge with a face covered in protruding blades), it is also a very satisfying one. As cheap horror films go, they don't get much cheaper, but Basket Case is one film where the low budget actually works in its favour.
It's the right length, shot pretty well considering the budget, and while it's about as tacky as it gets, there's some genuine moments of horror on show. Belial is a great character, and while his effectiveness was ruined by two shoddy sequels (with higher budgets and more horrific characters), in this first film he's formidable. Basket Case is an excellent curiosity for the discerning horror fan, and about as essential as it gets.