Firstly, yes it was hidden. Partly because there was a similar question here, and partly because it was too vague and unlimited. Especially your comment "Pokemon Simulators and online games related to pokemon are good too" - there are literally hundreds of these, and they all disappear as quickly as new ones appears.
Asking just "What are all the Pokemon spin-off games?" might be an OK question, since there is a fixed list of official Nintendo games (although there are tons of those as well). Ask that question if you like and we'll see how it goes!