These all seem like unfounded worries. The stuff with Pocket Pair is its own thing. And while they're going for a cozy vibe here, it's just a completely different kettle of fish from how Animal Crossing functions; even zeroing in on the minecraft-a-like "builder" genre I don't think there's any worries about it being so wildly successful that it overshadows everything else. And even if it did it's kind of like...doesn't really matter that much? DQ Builders hasnt had a game since 2018, minecraft is still an unstoppable juggernaut, and all the other ones that like the cubes & build stylings tend to be indie games which have smaller scopes anyway.This is one of the few times I have been hyped for a Pokemon side-game.
I'll admit, I don't really give a fuck about "cozy games" like Animal crossing, but the concept being explored with a Ditto is pretty cool. In fact, the main character being a POKEMON - especially a versatile one like Ditto - and using that to do all kinds of wacky things to interact with the game world is I think why I so excited for this. It also helps that Ditto has that classic weird + cutesy charm inherent to a lot of Japanese mascots that makes it really endearing - another good example of this is Myaku Myaku from the recent Japanese World Expo event.
I suppose this game will draw ire from people because of the recent lawsuit Nintendo targeted Pocket Pair with - which is pretty shitty imo. That said, independent of that BS, I personally am fine when are used to explore other genres. I do worry though that Pokemon's version of a "cozy game" will simply outshine all the other competition given how much more popular and recognizable Pokemon's brand and characters are compared to something like Dragon Quest or even Animal Crossing itself (despite the sales of New Horizons & New Leaf, I think the average joe will be more likely to know Charizard or Pikachu compared to Tom Nook or Isabelle for example). It'll be interesting to see if the sales of this game will reinforce this worry.
Realistically it probably won't even be a super insane run away success.
