*SPOILERS*
 
Just finished reading a write-up by Kirk Hamilton on Gamer Melodico about his numerous issues with Heavy Rain. It's a good read that summarized my issues with the game. You can find the read here, and I suggest anyone who's played the game look it over:
 

My only problems with Scott being the killer is he was my favorite character and I was hoping him and Lauren would be the ones to solve the crime.  I think him being the killer really takes the scene down with him and the baby down more than a few pegs.  Kinda hard to think that he cares about this child when the man gives little boys a slow, cold death.  Cold bastard betrayed me >_<.

Wasn't the motive that he was nuts? Also wasn't that explained several times that he was testing other fathers who couldn't ever save their sons? I mean maybe that isn't made as clear in all versions of the story but it seemed pretty clear that, although being a very thin motive, he was driven insane by his brothers death and his fathers complacency. I can agree that the type writer scene felt really off after the ending and was probably the biggest example of that choice not making much sense but other than that its perfectly fitting for a crime drama.

One of my biggest complaints, was the typewritter scene reveal (really cheap trick). I was hoping he was hired by the origami killer, not be him. The origin of origami was also disappointing, he got a book about origami... that's it? And what trailer trash actually grows orchids?

Yep the typewriter scene was a cheap cop-out. Worst part of the game for me. It didn't ruin it but that scene felt extremely lazy given what happens in the rest of the game.
 
It was the same as those old Saturday morning serials like King of the Rocket Men and Flash Gordon, when they would show the cliffhanger one way and then in the next episode it would show scenes that never happened in the previous week's cliffhanger to make the hero survive.

"My only problems with Scott being the killer is he was my favorite character and I was hoping him and Lauren would be the ones to solve the crime.  I think him being the killer really takes the scene down with him and the baby down more than a few pegs.  Kinda hard to think that he cares about this child when the man gives little boys a slow, cold death.  Cold bastard betrayed me >_<. "

This game certain brings out emotions, doesn't it. 

@impossibilium 
 
Yeah, the whole typewriter thing was kind of messed up.  I didn't destroy my experience but it certainly did color it.

Why is it that I have this feeling that even quantic dream didn't even know who the killer was until they backed themselves in a very tight corner... 
You see the game literally shoves the idea in my face that Im in complete control of all the playable characters... heck if control were like dirty socks quantic dream would be shoving it under my nose.  Having me shower, cook eggs, place plates GENTLY, and other numerous medial tasks... whilst pointless in the plot progression, gave me a sense of control, Yet when Soctt is revealed as the killer, sure he has motive which is explained, but I feel like this element of control is violently taken away from me and a gargantuan plot hole is torn wide open, here's why. 
 
Scott kills the elderly watch repair dude... Wait.. WHAT!!!  I don't remember doing that, I had complete control of Scott at this time, I DID NOT DO THAT! 
I thought MY CHOICES determined the outcome, Where was my choice here, where was my control. 
 
And then I too was infuriated later to find out that It wasn't all those choices I made and all that control I had that determined the outcome, but some stupid ability to accurately follow your flimsy QTE.  
 
I only finished the game myself 10 minutes ago... So I have a lot of anger and disappointed bellowing through me at this moment.  When calmed I will see if I care to elaborate more on this poor experience. 

@ Dovey: In regards to the typewriter repairman being killed, while you're waiting for him to go through his files there's a shot the zooms right into Lauren playing with a music box so I think that's when Scott kills him.  
 
Overall though there was only a couple of things that really annoyed me. I was surprised how natural the movement and interaction felt after some time with it. That said, JESUS CHRIST THAT FUCKING TUNNEL!  All the disorientating camera changes as you're crawling and Ethan suddenly doing a complete 180 when you're trying to turn left or right was absolutely maddening.

why is everyone being no negative with this game? 

"@ Dovey: In regards to the typewriter repairman being killed, while you're waiting for him to go through his files there's a shot the zooms right into Lauren playing with a music box so I think that's when Scott kills him. "

" @Newjack said:

"@ Dovey: In regards to the typewriter repairman being killed, while you're waiting for him to go through his files there's a shot the zooms right into Lauren playing with a music box so I think that's when Scott kills him. "

I totally just remembered that.  Doesn't that happen when you go into the back to "check" on the old man?  Now it makes sense. "

I'd like optimistic approach and think that Quantic Dream wanted the killer to be randomized based on your decisions. But because of budget/time/whatever, they were forced to go with one specific ending with Shelby being the killer. So all of the ground work that was laid out for the random killer mechanic, like the surprised Shelby finding Manfred dead scene or the multiple ways the ending played out, didn't fit too well with the new restricted plot.
 
Also, I felt really grossed out when Shelby kissed Lauren after I found out he was the killer.

" @Bionicicide:  Actually the reason he leaves origami is because his mother taught him and his brother when they were kids. He leaves them on the bodies as a memorial type thing for his brother. "

In the end I felt that Jayden's partner was in on it with Shelby or at least helping him cover it up.  He was quick to wanting to accuse other people (the religious guy, the thug from the meat locker, Ethan).  Also, if you get arrested after the type writer store...you come to find out that Jayden's partner and Shelby know eachother.  He says something like "If you find any evidence you'll let me know, right Shelby?"....Shelby looks at him under his brow and then walks off while Jayden's partner laughs.  Plus his utter disdain for Jayden wanting to find the real killer instead of accusing Ethan (at least in my play through).
 
I'm probably reaching....maybe I just want something a little more.  Making Shelby the killer was a little lame IMO as well.  
 
(and sorry...I can't recall Jayden's partner's name...so I just refer to him as "Jayden's Partner")

Double post but two more continuity things that aren't massive but seemed intentionally misleading: 
 
-Unless Scott was wearing a girdle under that trench- coat the character you fight in the night club is an extremely poor representation of his proportions. 
 
-Anyone get Jayden and the tanks on his desk? Don't really understand what I did to get it, is the implication that ARI is bleeding into his life? Because I resisted all possible chances to take triptocaine and didn't use the glasses on the final office scene any longer than was absolutely necessary.  
 
Also, for a while I was cooking a theory that Jayden had already fried his brain irreversibly even before you control him. ARI is the only sci fi aspect of the game, and nobody else ever acknowledges it in the slightest. I was half expecting it to be revealed as just a pair of sunglasses and a glove, anyone else ever suspect similar? Obviously the level of evidence he acquires is too detailed for that to really work, but when he started having Shining- esque hallucinations with the waiter (combination of drugs and ARI?) I wondered if perhaps he was using conventional means of clue gathering and deluding himself.