Just saying mentioning it by itself as you did above is too vague to be known as a game critique vs bragging.
Now that you clarified though, I agree, it's a bit easy regarding fighting and even easier regarding gunplay. It was advertised as more of a GTA style cinematic experience than full on fight game though, so it's not surprising it has one fairly easy difficulty level like GTA, vs several diff levels plus an unlockable one like Batman: AC.
That said, it does have extortion, just not to the degree Godfather does. Tower defense in AC: Revelations was complained about a lot and didn't really mesh well with the rest of the combat. As a result they're omitting it in AC3. There are their own versions of turf wars present too, just not in a DIY open world way. As for SR, I can't take anything in that game seriously as ridiculous as it is.
I would call this more of a stylized, movie themed action game than a full on fleshed out sandbox fighter game, a bit like Stranglehold was, only more polished.