Are there legal ramifications for using Metroidvania or DOOM clone in official marketing, or is it perfectly fine?

I noticed on Steam there is a "Not a Metroidvania" bundle, and it just strikes me as weird. Not necessarily wrong or bad, but I just can't think of another time I've seen a large game storefront actually use the term Metroidvania. Roguelike gets used a lot, but I'm pretty sure Rogue is open source and/or the companies that owned the rights have long since stopped caring because Rogue itself is not really a valuable IP at this point. Anyway:

https://store.steampowered.com/bundle/7135/Not_a_Metroidvania/

I'm not a lawyer, and have no idea what the bounds of trademarks are. The Castlevania connection is tenuous, but "Metroidvania" does entirely contain the made up word "Metroid" that Nintendo owns the trademark for. I know you can't just call your game "Metroid", but I'm curious how far you can actually go. Can your advertising use the term "Metroidvania" and favourably compare a game to Metroid as much as it wants, so long as the game's title doesn't actually contain "Metroid" or obviously rip off Metroid art? I'm genuinely curious where the line is on using other people's trademarks.

I doubt there'd be much of a fuss made over it. I remember growing up car companies would always say "better than the other leading brands" and such, whereas now they explicitly mention their competitors by name and car model, so I assume that as long as someone couldn't reasonably be lead to believe that these games were in the Metroid or Castlevania series I doubt they'd get in much trouble for it. And I assume anyone who's familiar with the "metroidvania" term is probably going to to pretty aware of what they're getting.

I guess it has more to do with Nintendo seemingly not caring rather than the bounds of a trademark. Kind of like how Google doesn't like people saying "I'll Google that" but they don't really do anything about it. I bet if someone put out an actual game called "Extreme Metroidvania 2018" than they would get involved. And "Metroidvania" has been used a genre for so long I doubt Nintendo could do anything about it.

I can tell you that the creator of Brutal Doom started a Patreon to make Doom mods and Bethesda/Zenimax sent him a notification that he wasn't allowed to use the name Doom, and so now he has a Patreon to make video game mods (even though its setup for Doom)

My woefully misinformed (and American-centric) guess is that "Metroidvania" is fine because that specific name hasn't been registered (after all, there's no Nintendo game called "Metroidvania"). At this point there's probably enough public, non-trademarked usage of the term that nobody, even the creator of the games that form the portmanteau, could reasonably make a claim to it. The comment about Doom is a different story because Doom is a specific game with a clear owner, so you can't just go using that name and game for your own commercial purposes.