It's actually kind of hilarious how angry people are at Enchanted Portals for ripping off a rip-off.
"Did they ask the creators of Cuphead first :("
Idk who did Cuphead ask?
Then there's the fact that that the character designs and animation Cuphead took from were often quite overtly racist, and in tweaking them just enough to put in the game, Cuphead whitewashed that.
But that's an essay someone else has already written: https://unwinnable.com/2017/11/10/cuphead-and-the-racist-spectre-of-fleischer-animation/
I mean, if it's all public domain, who gives a shit if another game rips it off?
And if it's that important to give credit to creators of original content, Cuphead's entire aesthetic is ripping off, I mean, paying homage to, original creators.