Playing to learn part 2

What i learned from the Choice  of games and genres is that games that are action are more fun and interesting because when you loose you just want to play again you don't want to just quit because you are into the game.Some game features that i noticed was that they all have a enemy ether like a person or a thing but they all have a obstacle and some games are really confusing.I have some questions: If we are making a action game do we have to have a obstacle?.