Yes, it is entirely possible to finish this game -- and most games of this type -- by plowing through the main story. But one can also plow through a $60 plate of filet mignon like it is a McDonald's burger.
Every game that is story driven and mission/quest driven has the difficult job of controlling the pace of the game so that the player is entertained for many hours, but not left feeling like it is a grind. Unless, of course, the game is marketed towards an audience that wants a grindy game.
Because players have a varied opinion on how long a game should be, how grindy it should seem, and how much time one has to balance work and play, we have this game structure that has main story and side missions and gigs (which are essentially bounties).
This format tends to serve a wide audience fairly well. Casual gamers can finish it in a way that fits into their personal schedule, and feel a sense of accomplishment even though side missions may be left uncompleted., while players that are completionists will complete everything.
This game also has a nice design such that it is able to played with a few varying play styles. You can approach it as a stealth came completely, or just minimize the use of guns, etc. or you can run 'n gun right through it.
My personal opinion is that this game is a lot more immersive when played with more emphasis on stealth and skills, and not focused on gunning.
It took me about 80 hours to "complete" the game to a degree that I didn't really find I was getting much out of it,, and then I began a replay as a female character, etc.
I am not usually one to play through a game like this more than once, so that it makes me want to do that is a good achievement.
It is a shame the game is considered a complete failure on the console (especially Sony) platforms because that really does put a sour stench in the air. People who have a good experience and come in these forums to talk about that, tend to get clobbered by those that feel ripped off.
But in my experience, the bugginess of the game is not out of line. Yeah, the save file size issue is a big failure, and I was not affected by it. I found some of the missions had some time wasting bugs, which left me wondering how it got past testing and into production. But I would not be seeking a refund, or trying to drag the studio through the mud any further.
