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.
Memetic Mutation - In Japan, there's many remixes of the NES version's main level music, and the Spelunker himself shows up in many remix videos, such as this one. The fragility of the protagonist is also memetic.