I have to say that "Red Snow" is one of your best works so far. I like the storyline itself and how much time it allows itself to take so things become clearer. The sound mixing is quite good, the soundtracks are used well, and the animation has improved by a long shot over the original Pretty Blood episode, "Rinny".
Issue-wise I feel that the sound effects from the game Undertale are weirdly misused here. Hearing the character's "voice" go from 'Asriel' pitch to 'Flowey', 'Toriel' or the human's pitch (which is used to describe things rather than being a character's dialogue) feels off and takes me out of the experience somewhat. It's a mild complaint, however.
The plot does quite well in establishing a lot of the characters. My favorite is Bloon, since he knows how to handle himself and generally is a very wise Malino. (It's sad knowing his fate. A real shame.) Rinny is despicable in every possible manner. She's been portrayed murdering the family of a little girl before as well as her own daughter, but now she stained her hands with an entire family, including an elder and a young child. It's disturbing on many levels. Seeing Rinny cry for mercy after committing heinous acts and then having them committed back on her through Luny is not only hypocritical, but extremely cowardly. I thought it was hard to make Rinny any more despicable than she is already, but now I only want to see her die no matter what, though eternal torment would be better.
The animation is squeamish not only because of the gore, but also because of the establishment of characters. I found it a lot more bearable when the characters we were introduced to were characters we knew nothing about. Characters like the Twins and Pompom did not deserve to get tortured, but knowing nothing about them made watching them suffer more bearable and watching gory deaths of cartoons akin to Happy Tree Friends is oddly relaxing for me at times. Characters that we learn about such as the family here and characters from "Dream Terror" not only do not deserve to be hurt or tortured, but we learn so much about them that we wind up rooting for them instead. It's hard to re-watch any of the episodes after the first time and it only leaves a depressing pit in my stomach when I think about them.
Still, "Red Snow" is very well done and left me on the edge of my seat with a lot of interesting suspense.