Hileo20 said:
I don't think it's the same. Fantasy hack and slasher's are built around the three established main classes from tabletop RPGs such as D&D, Warrior, Rogue, Mage. They may have different names or be subdivided into, say, Battle Mage or Healing Mage, Thief or Assassin etc, there are far too wide a range of superheroes to say that there are any forms of 'hero type' especially from a role playing standpoint.
A good open world superhero game would be able to let you select everything about your origin story, your powers, your costume, and your philosophy on life and crime fighting. What you're suggesting would give you (for example) the Batman Type, the Superman Type, and the Question type for variety's sake. They each come with a pre-made backstory, a pre-made motivation, and the only customisation you have is via costume and actions, which is not designing your own superhero, it's playing dress up with someone else's superhero.
That is definitely your opinion as to whether those games are MMOs in a single player setting. BALDUR'S Gate I find to be almost like playing jRPG (or at least it did when I last played it), Fallout 3 is just another wRPG, a good one, but I never felt like I was playing online. A good single-player aping an MMO makes it feel like you are online, a la .hack, otherwise it's just an RPG. It might be a good RPG, but it's not mimicking the feel of an online RPG.