Each to their own, of course, but I don't personally agree with the overwhelmingly negative sentiment around Hyperia's theming, from what I've seen of it. I apologise if that's controversial, but that's my honest view from what I've seen.
I grant you, it doesn't look heavily themed, but I think the plaza, queue and station look perfectly nicely styled and landscaped, personally. For the most part, I think that the bits guests walk through look perfectly presentable and quite nicely done. I think the word "breathtaking", used in a previously embedded Facebook post, is more hyperbolic than I would personally go, but I think it looks nice enough. I quite like the gold around the area, I don't dislike the station exterior with the black and gold trim, I think the station interior has been done quite nicely, I quite like the dispatch sequence, and overall, I don't personally dislike it. Sure, it's not going to blow any minds, but I don't think theming is really this coaster's primary USP.
If we're doing like-for-like station comparisons; I'd argue that I can think of at least 2 major coaster station interiors at Thorpe that I would say look no objectively better than Hyperia's. Stealth literally doesn't have one, and I don't see how Inferno's station interior is any better than Hyperia's seeing as that is also a tin shed with a dispatch sequence that I would argue is lower-calibre than Hyperia's.
With that being said, one thing I will say is that from what I've seen, I'm disappointed with how the area under the ride itself looks, particularly the lake with the splash effect. That splash effect looks like more of a damp squib every time I see it what with how it's hidden behind a huge fence, and I think the lake with the reeds growing in it and the muddy ride area look quite unkempt. I know that the area under a roller coaster is hardly going to be the Hanging Gardens of Babylon, but some grass or something and some semblance of a more tidy appearance might have been nice in this area. However, I concede that this probably won't be too much of a concern when you're on the ride itself, and it may begin to look a bit better once the ride has settled in a bit.
The one caveat I should add to all this is that I haven't seen it in person yet and am simply going off the photos and videos. When I do get to see it in person, I may hold a different opinion.