I'm about 50% into the story, so i can't say for sure where the story will go by the end, however i can already understand the critique about the lack of focus of the plot, as it seems to be about everything and nothing (despite having some of the funniest moments in any R* game), all three characters plow through the (fun and varied) missions with the need to make money that is indefinitely withheld, or being blackmailed by someone who's even a bigger asshole than you.
Standard GTA trope, that is constantly used in both GTAIV and RDR, too.
The thing is, you really couldn't play GTAIV without breaking the narrative, even if you stopped at red lights, walked everywhere and stood in front of the urinals every once in a while, simulating Niko taking a piss.
You couldn't because the shit the game required you to do, broke up the narrative, and it did because it's a videogame and expecting the same level of tightness you expect from a movie or a book is silly.
Now i'm sure Bissell is more aware of this than i am, since he writes games on the side, but it really doesn't matter if you think Niko going on a killing rampage "breaks the narrative", when even in a linear game like Bioshock or Uncharted, you can stray from the critical path to collect coins and meaningless, game-y shit; when you can stand in a corner facing the wall, jump on the spot for 40 minutes or stare in silence into an NPC's awkward dead eyes for minutes.
The extent developers go, to try and polish up this aspect is insane, and it's still completely broken, no matter what they come up with.
Even a super guided experience like Heavy Rain was easily broken if you sit in a chair for too long on stand facing the wrong direction.
This is an obsession that i feel too in a way, but that i think we're losing far too much time and energy over, when it really isn't that important, since people that play know how to differentiate the two aspects of a videogame anyway and, once you're ready to accept a less polished narrative experience, you'll be ready to narrate your story through pure gameplay, i feel.
Niko wasn't what R* wanted him to be, Niko was what he was when I was playing as him, 'cause that's what a videogame is about fundamentally, in my opinion, and no level of polish can fix that.
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As for GTAV, i didn't finish yet, as i said before, but i think the game is about itself more than anything else, consciously or not.
The game feels, to me, very much like a therapy session for GTA and all its trappings and tropes, down to the three characters' archetypes, the clash of tones (stunningly poetic art direction on crass humor and awkward satire) and everything else that, in minor form, plagued even Max Payne 3 and Red Dead Redemption.
The game feels very much like the sum of "everything GTA" and is incidentally what R* has been promoting the game as, this whole time (the biggest, most ambitious GTA yet etc etc).
I think looking for a thematic inside the game's plot will miss the bigger and more interesting point of the game, and i wonder if it's just an ironic coincidence, that in this game, therapy and psycho analysis are recurring themes.