It’s an extremely difficult game with design paying tribute to late-1920s-to-1930s cartoons and includes some of the dark humor many cartoons of that era had. IOW, while it is colorful, Cuphead is aimed more at adults than kids.
Everybody's got their hobbies and I respect that, so long as it doesn't take over your life and keep one from doing more productive things. I know too many kids that play these games constantly and their education and development suffers. When I see adults playing these games while still living with their parents, I shake my head. Grow up guys.
I never allowed video consoles in my home when my sons were growing up but did allow them online games in limited doses. Both of them moved out in their early 20s and are doing very well for themselves and yes, they both ended up getting video-game consoles but I say good for them, as they are on their own now and they can do as they wish as it is their time and it is on their dime.
But unlike others on this thread, I'm not condemning it. Everybody should have a stress reliever that does not overly tax the brain. For some it's doing jigsaw puzzles or crosswords. For others, it might be playing a musical instrument or fishing. My guilty pleasures include going to the casino and playing blackjack or slots - which understandably others might see as foolish. But I like it and I need a full day in a casino every now and then to clear my head and forget about the rest of the world for a few hours.