To me I find the "Comic Style Story" to be disturbing. That seems to be a sign that they are going to be abandoning pretty much all pretensions of serious horror. Largely because horror comics endeavor to get away from the "comic style" themselves.
Truthfully I would think they would need to be going in the other direction, away from a comic-book-like way of doing things.
As far as "Dead Space: Downfall" goes, my thoughts were that it seems to have been done by a totally differant team of people from the guys that did the game, and neither team talked to each other much. While the movie did clarify a few things, such as the constant, ambient, psionic attack taking place alongside the attacking monsters (something also a key element of "No Known Survivors") I felt that a lot of the character and weapon designs were considerably differant. I for example get the impression that the team doing the animation was told that one of the main weapons in the game was going to be a "Plasma Cutter" yet was given no indication that it was more like a welding gun than an energy blade.
What's more I had kind of hoped that the movie would find some clever way of giving what amounted to exposition to explain some of the game play elements. For example one of the things that bugged me about "Dead Space" was the various store units where Issac can just saunter on up, drop a bunch of looted credits, and produce armor and weaponry. There is some basic implication that it's a replicator system that needs patterns (hence the schematics) but still, one has to wonder why nobody else bothered to use this. I mean the first thing someone like the #1 Security Officer would do in a situation like that would be to disable to money/security interlocks and start using it to churn out whatever weapons were needed for survival.
All that aside the very existance of such things was a bit weak, a gameplay mechanic with a flimsy justification, and no relevency to the storyline or how things play out. That said if they could have worked around that idea in the movie and made it seem more plausible, along with other similar "problems" with the game/concept it would have made the film more of a companion to the game as intended.
As it was, I consider the movie an epic failure. I suppose if you judge it totally on it's own merits it's not bad, but when you look at the game and try and view it as a prequel story it just doesn't work. Despite some common elements when it comes to the details they might as well be two seperate univeses.