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.
Broken Record: Everyone in the story can't shut up about how awesome yet how horrific Kurtz and his methods are.
Everyone Is Jesus in Purgatory: Considering how dense and omnifaceted the story is, this happens pretty often. There's a TON of ways to interpret Heart of Darknessnote you can easily find Marxist, deconstructivist, feminist, or post-colonial interpretations, just to name a few, and many odd ones are surprisingly well-supported (though many are not). Here's an example.
Values Dissonance: The native Africans are repeatedly portrayed as violent, ignorant, subhuman cannibals... and those are the good ones.
They're always shown as better (or at least, more humane) than the European colonists.
Fridge Horror - The General Manager purposefully wrecked Marlow's steamer before he arrived so that aid to Kurtz would be delayed. After all, it was "too stupid - when I think about it - to be altogether natural".
Awesome Music: One of the very first games to incorporate symphonic musics, to reinforce the cinematic feel.
Demonic Spiders: Nearly anything to be precise. Everything, absolutely EVERYTHING, has a way to One-Hit-Kill you. Shadows eat you, Worms will emerge from a wall, snap you and feast on you in a matter of seconds. Shadows in armor can use "The Power" in various ways, flying shadows likewise and they double for goddamn bats. And that are the few creatures you can actually HARM. The shadow spiders are a perfect match: you usually fight them while climbing, limiting your movements; they drip poison on the handholds that can make you fall, and they evade any shot you can fire at them unless you let them come very close.
Goddamned Bats: The shadows mostly, but flying shadows are a perfect match: They fly, they evade everything you throw at them if its the last one and they can throw fireballs that kill you in one hit. Ask anyone about them and they will say they hate them with a passion.
Good Bad Bugs: If Andy crouches such that his rear end pokes off the screen, enemies will not come from that side.