Overall, it's disappointment. I think the think I didn't realise was - after finishing DanganRonpa 1, I wanted to know what happened with the world. I wanted to see outside, see the world ravaged with despair, find out what happened to the characters etc.
But the more that's been revealed about the world, the less interested I've become. I preferred seeing Junko as somewhat of a mystery; a person who turned all these characters to despair because that's who she is, the Ultimate Despair. I wanted her to chip away at their psyche using her skill and their flaws. Going back and seeing how she turned the cast of DR2 using brainwashing really took away some of the appeal of that.
With regards to the conclusion of the Future Arc, I actually quite like the idea of full hope being just as bad as full despair, but the way it's been handled... I dunno. Just feels half-hearted.
I think my biggest disappointment with it is that it makes the previous two games less special, knowing what I know about the anime. I think I'll have to take a long break from everything Hope's Peak Academy related and come back years later to see how I feel but yeah, right now it's just a shame.
And aside from all this, there were just too many important parts of the plot that were rushed through for me. For example - in the end I quite liked Chiaki being the centre of the class then being executed as a source of despair for them. Sure, I preferred the idea that Junko turned them one-by-one by picking on their weaknesses, but I liked the tragedy of the Chiaki situation too.
Except, they glossed over it far too much. We saw them beginning to bond together and Chiaki taking control, then Chisa got moved to the reserve course, comes back and "hey, Chiaki helped us all bond even more, here's a few pictures!" I wanted to see that. I wanted it to be explored properly.
My biggest grievance is the mutual killing of the Student Council. Holy crap, was that glossed over. Junko turns up, shoots one of them dead and says they have to kill each other or die, suddenly they all start massacring each other in horrible ways. Why? How did it happen so quickly. Having played DR1 & 2, I can genuinely believe that people can turn to despair in a situation like this, but so quickly? Nah. Really irritated me. I wanted to see that - and those characters - developed more.
So overall, a disappointment. It certainly had its great moments and I have enjoyed tuning in every week, but as part of the overall DanganRonpa storyline, it's been a let down and not what I'd hoped for as a "filling in the gaps" storyline.