Anime - Yes, it's for children. They know kids get older, so the original fans have moved on, but that also means newer fans are getting old enough to enjoy the show - hence the constant "repeats" on newer episodes.
Manga - Not strictly. Death, illness, and violence have a part in the various mangas' storylines. While it's not incredibly graphic, it still contains frightening moments, such as Giovanni killing two Magmar after their loss against Red. Along with that, the manga is usually great when it comes to displaying various moves of Pokemon - showing the harmful affects and various ways of pulling them off that you can't do in the games, without the random explosions you always get in an anime.
Games - Yes and no. The games are simple enough for children to play, but they're challenging enough for teenagers to enjoy. As for adults - well, only self-loving douches complain about a game series not being "challenging enough" when the series was made for teenagers. The games also share traits with the manga. There are cases of death (cubones mother), impending doom (Frosslass falls in love with travelers then freezes them so they don't leave), the impossible (ressurrecting legendary folklores/Gods), and various horrors (you're supposedly a 10-13 yo kid running all over a region collecting these creatures that are capable of massive destruction, treading massive oceans, exploring dangerous caves, climbing volcanoes, and fighting terrorists - all without a separate change of clothing).
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