The original part is the specific formulation. Pretty much all games are mashups of other games anyway. Palworld found a formula among popular games that really struck a chord with people, and they executed on it pretty well.

And yeah, I've seen extensive portions of Palworld since my SO is really into it. My SO doesn't care much at all about Pokemon, Breath of the Wild, or Fortnite, though they really like Palworld. That alone is a pretty good argument for Palworld being distinct.

Nintendo is mad that Palworld did a great job with some of their ideas, and I think they want a piece of the action. I don't think they're concerned that anyone would mistake Palworld for any of their IPs, they just want some cash. I'm interested to know which patents they claim Palworld violated, because it's honestly really rare in video games for patents to actually be enforceable because there's so much prior art and a lot of variations in how mechanics can be used.