Alright, just completed the game. Analysis a-go-go!
Hotline Miami isn't just a game about violence. It's a game about the cycle of violence.
Let's start with the original protagonist. Jacket/Hitman/Richard. Originally he was a cipher, someone we had no idea about. Similarly, his friend at the store/bar/pizza place/VCR Palace was also unknown apart from a few cryptic references. Then we learn they were actually war buddies fighting against the Soviets. Everything falls into place: why Jacket was so good with weapons, the nature of his relationship with the clerk, and so on and so forth.
In the second game, he's a ghost. He's in prison, and on death row at that. But his previous actions influence everyone in the game. The most obvious would be the Fans and I don't have to explain them, but it goes deeper. The Actor wouldn't be acting in Midnight Animal if Jacket didn't kill anyone. The Russian Mafiya boss wouldn't be trying to impress his father with risky rampages if his father wasn't killed by Jacket and thus unable to keep him in check. The Detective wouldn't be reduced to a psychotic killer in the guise of a police officer if Jacket didn't have so many imitators. Hell, the entire city of Miami seems to have become a nest of rampages and insanity, mainly thanks to Jacket.
The violence starts in war, the 'natural' place for violence. Then Jacket is recruited into 50 Blessings and brings the violence to the streets, which causes the spiral. He's the patient zero for the outbreak of violence in Miami. Without him, none of the events of the game would have happened. Miami might not have been nuked, if 50 Blessings seriously relied on Jacket for the survival of it's operation. Which is doubtful but possible.
This is why Richard the mask appears regularly, taunting most of the player characters. That was the mask Jacket was arrested in, and the most distinctive. The mask personifies everyone's fears. The Mafiya hitman's dreams of freedom is interrupted by Richard talking about how the road they're traveling on is a dead-end. The Mafiya boss cracks open the vault only to find his dead parents and grandfather, who is wearing the Richard mask and telling him how he will never match up to his father. Finally, he appears to Richter telling him that everything will get much worse from then on. While the others resist... Richter accepts his fate. Richard says the last words of the whole game: that letting go of life is not as hard as you think. I may be misquoting him, feel free to correct.
Then, 50 Blessings (Jacket's masters during HM1) assassinate both the Russian and American presidents. The world falls into an inter-continental nuclear war. We see visions of the characters that are left alive being burnt to a crisp by the nuclear attack. In the end, we see Jacket in his jail cell just before the bomb wipes him off the map.
I think that last image summarizes how everything went. Jacket, for all his efforts, has lost everything directly because of the violence he committed. His girlfriend, his house, his freedom, and at last his life. No-one has gotten what they wanted. Everyone has lost everything. Whether that's a shame or not is up to you.
By the way: in the dream the Detective ends up having, he meets a bug-eyed man who is apparently 'the Miami mutilator'. I think that man might be Jacket, or at least a very strange version of him created by the Detective. Is that how the Detective sees the man who started all this madness?
I like games where some things are left up to the player. Hotline Miami 2 remembers this, thankfully. Well, at least some of the time. By the way, does anyone know the music that plays in the End Credits?
Thanks for this, and all the other plot discussion. Seeing other peoples' interpretations really helped me understand what I just saw. I also missed a lot of little things. Posting to watch, also.
I really enjoyed the plot, but like a lot of people, I was super frustrated by the huge levels full of gun-enemies. Particularly those looong hallways where all you can do is inch forward at max shift-look, because there might be a patrolling gun-enemy just beyond your vision. Even shittier because there usually actually is one, or even two. The game punishes taking any risk at all.
Edit: I even went back and played a couple levels of HM1 just to make sure I was remembering right. I was, it flows a *lot* better and rewards good reactions rather than forcing you to make a plan for every room due to excessive enemy overwatch from offscreen. There are still gotcha-windows, but the floors are small enough that you can actually see them coming... Or at least remember them easily, and dying isn't a big deal. I planned to only play two levels (on a touchpad, no less) and ended up playing 5 and having fun.