There's a problem with that, even if you patent something you can't take legal action against someone who already had implemented in their systems what you patented.
Nintendo could sue a lot, a LOT of people regarding the Pokemon brand because they are creators of Pokemon fangames (the Spanish-speaking community is the one with the most and the best quality), even though they protect themselves under the fact that they are totally free projects, Nintendo could still take them down, but it doesn't do it because they don't care.
There was the case of Pokemon Uranium that was taken down for using online systems, but it was a long time ago. Even on Steam you can find many copies of Pokemon that could be taken down, but they don't give a damn.
The moral of the story is... Don't mess with Nintendo and they won't mess with you.
In Japan you can. You can't even expedite patents in most countries, but again, in Japan you can. And from what I understand, modifying existing patents or making derivatives of them--not making brand new ones--before suing someone is an extremely common practice when you
are going to sue someone.
While this is annoyingly classic Nintendo and everyone should hate them for it, unfortunately the law and Japanese law in particular allows this kind of bullshit. No one knows the truth obviously, but it seems they're just trying to legally and financially bully Palworld's devs which they can certainly maintain far longer than Palworld's devs can resist.
From what we understand the outcome might mean at worst a large payout and at best a modified version for Japan unless Nintendo uses a positive verdict as the basis for lawsuits in other countries.
As for the free projects... not sure what you're talking about. Nintendo has taken down a TON of free projects over the decades... it is something they are literally infamous for. They used to do worse, like copystrike youtube channels that showed any amount of footage featuring their games, including holding the game up. And youtube would comply.
Even on Steam you can find many copies of Pokemon
You're going to have to point them out, because while there are other monster collecting games I'm pretty sure none of them are anything actually like pokemon and certainly nowhere near Palworld's closeness. The devs knew what they were doing when they made those designs. I like palworld but there is no way a sane person could argue against the fact that a lot of the pals are simply redressed pokemon while many others simply channel the exact same concept in a slightly different way.
Imo the game is so different that Nintendo shouldn't be able to sue for copyright infringement, which they aren't. But as soon as everyone started calling it "Pokemon with guns" I knew it was only a matter of time before something stupid came out of it.