These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Narm: Conan's fight with the lizard/ape man, who tosses big rugged manly Conan around like a rag doll when he isn't pimp slapping him, isn't anywhere near as scary, frightening or intense as it's supposed to be due to some really, really, really bad fight choreography. And when you consider that Conan does a better job against the demonic god Dagoth in the climax his fight with the lizard (gator?) ape man just looks even more ridiculous.
Replacement Scrappy: Malak, obviously being a replacement for Subotai, didn't sit well with the audience, his role being a string of never-ending bad jokes and acting like a doofus. Weirdly enough he seems to have some or all of Subotai's memories, enough to identify a specific camel on sight.
The Scrappy: The character Jehnna was widely panned for being an annoying whiny and screaming Royal Brat.
So Bad, It's Good: Conan the Barbarian was a very popular, deeply thought out, and well-received movie. Conan the Destroyer...wasn't, but that's what makes it fun.