games are what you makme of it. There is no such thing as an "easy" or "hard" game. its all based on the player. like my cousin can beat any halo game on legenday mode easily. I can't. But... I can beat most rpg on high settings. there are 2 meaning to the term casual
casual as in "easy" meaning your not a gamer per say aka farmville.
or casual meaning your a gamer but don't have to much time to play. levequests in ffxiv are a good example.

SE is more going to a less time consuming game. you can still have a "hard"game that is not to time consuming.