Form - Nothing bad, nothing great.
F/X - The film really shines here. It's not afraid to take some ridiculous leaps into the surreal. In the first ten minutes, a corpses hand gets cut off, the same corpse is gutted, a man steals the heart out of another corpse and proceeds to eat it, and the same man jumps out of a window on the tenth floor of a hospital building. The last visual effect is probably the best reflection of the film as a whole: the dummy they used for the fall doesn't survive the impact, with it's arm clearly popping off. In the next shot, the man is seen on the ground, fully limbed with some blood trickling down his body. Does it make sense? WHO CARES, THAT WAS FUCKING AWESOME!
Acting - The English dub actors are amazing.
Mise en scene - They're mostly in the jungle, but one scene in particular is pretty striking: the cannibals paint one woman with flowers all over her naked body, then walk her through a delicious cave setting to a giant slab prop that must be seen to be believed.
Quotables - Zombies are never called zombies in the film, although they are referred to once as "those strange creatures who saved us".
Cool stuff - When the main characters reach the jungle, they bring three natives with them. They're those characters you know were just written in to be killed, and boy do they kill them off quickly and in spectacular fashion. Zombie wearing a human's scalp as a wig, death by speed boot motor, guys jumping out windows, tons of cannibalism, zombie's all making the exact same "uUHHHHHHhhh" noise, it's all here.