It's charming. I'm not familiar with either fandom - I've somehow missed seeing the Sentinel (but know a bit about it because there's such a big fandom), and Bamse seems to only have hit Denmark after I left. The use of English and Danish was very clever and the transitions were both smooth and at the perfect times.

Minor nitpick: I don't know how realistic the Peruvian part is supposed to be (given it relocates to somewhere in Denmark) but the Mayans weren't in Peru. You'd need Guatemalan jungle or similar.

We actually have some jungle I suppose - rainforest - around here and the thing that I notice about rainforest is that it's cooler - if you're walking in a normal forest and you come into a rainforest pocket, it's humid but also cooler. And definitely darker. The change can happen in a few steps, it's quite dramatic. I don't really know how it would work between a Danish forest and rainforest though, Australian forests are quite different!