Here is my SPOILER FREE review of the first episode of the Heavy Rain Chronicles.
It plays much like one of the little chapters within Heavy Rain. I have to say that the length is disappointing considering its price tag. For me the DLC took me approx 20 minutes and that was with me taking in the experience and meticulously exploring all. Despite this misgiving, on the whole the DLC is very intense and enjoyable experience.
The 'Taxidermist' despite its length manages to include the same tense situations you find yourself in during Heavy Rain (think doctor death). At several points it had me genuinely creeped out, more so than at any point in the main game. Something that may be jarring is the voice of Madison. You will notice that the voice work is different than the one in the main game however you will soon become accustomed to it. Also the thought system is different, I suppose as this was created as an E3 showcase it is in an early stage but I found that it is an improvement. Instead of thoughts floating around before you activate certain points to continue, the thought system in the 'Taxidermist' differs in that it is more contextual. An example of this is in the corridor she will comment on the decor of it but walk into the bedroom and thoughts specific to the location will appear.
I feel it would have been better if after downloading the 'Taxidermist' it would appear in the main game's plot because it would make sense but instead you have to go to extras. The DLC does include some bonuses such as a cringey voice actor video (I believe it is the audition of Lauren) and some concept art.
All in all the DLC is of high quality although not really deserving of its price tag. Replayability is limited however there is always the lure of seeing each of the multiple endings. If you were expecting an epilogue movie, such as the ones featuring in the main game, then you may be disappointed as the DLC ends with a newspaper article.
If you are a fan of Heavy Rain then this is a must buy just so you can get a few more minutes of glorious drama. If not then I would pass.